01. [ELEX]

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. An alloy of 22 percent iron and 78 per cent nickel. A. Permalloy B. Alnico C. Constantan D. Manganin

. Electric field intensity is measured in A. volts/meter B. Newton/meter C. Newton-meter D. Amperes/meter

. Lenz's law is the consequence of the law of conservation of A. Energy B. Charge C. Field lines D. Momentum

.A law stating that the magnetic susceptibilities of most paramagnetic substances are inversely proportional to their absolute temperatures. A. Curie's Law B. Child's Law C. CR Law D. Curie-Weiss Law

.Flux density is measured in A. Tesia B. Weber C. Ampere- turn D. Maxwell

.If the magnetic material is located within a coil through which alternating current (60 Hz frequency) flows, then hysteresis loops will be formed every second. A. 60 B. 120 C. 30 D. 180

.One farad equals A. 1 coulomb/volt B. 1 newton/coulomb C. 1 newton-meter D. 1 volt/second/ampere

.One of the common application of an air- cored choke. A. Radio frequency B. Audio frequency C. Power supply D. Power transformer

.The permeability of permalloy is A. Very much greater than permeability of air B. Slightly greater than permeability of air C. Slightly less than permeability of air D. Equal to the permeability of air

301. What composes all matter whether a liquid, solid, or gas? A. Atoms B. Electrons C. Protons D. Neutrons

303. What is the smallest element of a matter? A. atom B. molecule C. crystal D. wafer

304. To determine whether a material can support the flow of electricity or not, we need to examine its A. atomic structure B. physical state C. molecular structure D. chemical composition

307. Known as the simplest type of atom. A. Hydrogen B. Oxygen C. Helium D. Nitrogen

311. The nucleus of an atom is normally A. neutral B. positively charged C. negatively charged D. either positively or negatively charged

312. What particles that revolve around the positive nucleus? A. electrons B. protons C. neutrons D. electrons & protons

313. In electricity, positive electric charge refers to ____________. A. protons B. neutrons C. electrons D. atoms

314. What is the charge of an electron? A. 1.6022 x 10^-19 C B. 9.1096 x 10^-19 C C. 1.6022 x 10^-31 C D. 9.1096 x 10^-31 C

316. Protons are about _________ heavier than electrons. A. 1,800 times B. less than thrice C. less D. twice

318. The maximum number of electrons (Ne) that can occupy a given shell (n) is determined by the formula A. Ne = 2n^2 B. Ne = n^2 C. Ne = 2^n D. Ne = 2n

320. Maximum number of orbiting electrons at the first or K shell A. 2 B. 4 C. 6 D. 8

329. Electrons at the conduction band are called A. free electrons B. valence electrons C. deep state electrons D. shallow state electrons

332. Which material has more free electrons? A. Conductor B. insulators C. mica D. dielectric

333. Which material has the least number of valence electrons? A. conductor B. semiconductor C. insulator D. semi-insulator

335. A good conductor has how many valence electrons? A. 1 B. 2 C. 4 D. 8

341. From the combined energy-gap diagram, which material has the widest gap between valence band and the conduction band? A. conductor B. semiconductor C. super conductor D. insulator < View Answer: 342. From the combined energy-gap diagram, which material has the smallest energy gap between valence band and the conduction band? A. conductor B. semiconductor C. super conductor D. insulator

344. The difference in energy between the valence and conduction bands of a semiconductor is called A. band gap B. extrinsict photoeffect C. conductivity D. energy density

345. The energy gap between the valence band and conduction band of a conductor is in the order of A. zero electron volt (0 eV) B. one electron volt (1 eV) C. five electron volt (5 eV) D. ten electron volt (10 eV)

351. Ion is __________. A. an atom with unbalanced charges B. free electron C. proton D. nucleus without protons

354. An electrical insulator can be made a conductor by A. ionizing B. electroplating C. oxidizing D. metalization

361. A structure for solids in which the position of atoms are predetermined A. Crystalline B. Polycrystalline C. Lattice D. Non-Crystalline

365. Ideally, all atoms have the same number of positively charged protons and negatively charged electrons, and is therefore considered as A. electrically neutral B. physically stable C. magnetically aligned D. technically rigid

366. When the charge of an atom becomes unbalanced, the atom is said to carry A. Electric charge B. Magnetic charge C. Electromagnetic charge D. Electrical current

367. A charged atom is also known as A. ion B. anion C. cation D. domain

368. An atom or group of atoms that carries a net electric charge is called A. ion B. anion C. cation D. domain

377. One Coulomb of charge has how many electrons? A. 6.24 x 10^18 electrons B. 6.24 x 10^19 electrons C. 62.4 x 10^18 electrons D. 62.4 x 10^19 electrons

378. Coulomb is the SI unit of charge, how about in cgs? A. Statcoulomb B. electron volt C. electron unit D. static unit

379. Statcoulomb is also known as A. electrostatic unit (esu) B. electron volt C. electron unit D. static unit

380. An isolated body under normal condition is always A. neutral B. positively charged C. negatively charged D. ionized

383. The rate at which electrons pass a given point in the circuit gives the magnitude of A. electron current B. magnetic current C. drift current D. diffusion current

384. The unit of current. A. Ampere B. Ampere/sec. C. Ampere-sec. D. Ampere-hr.

385. The unit Ampere is equivalent to A. one Coulomb/second B. one Coulomb/min C. one Joule/sec D. one Joule/min

388. The bigger the diameter of a wire, A. more current can pass B. less current can pass C. more heat is generated when current flow D. the higher is the electrical resistance

391. The longer the wire the ________ is the resistance A. higher B. lesser C. harder D. smaller

393. The amount of resistance that a wire has with regards to the flow of electric current A. is less for a conductor than for an insulator B. is less for an insulator than for a semiconductor C. is less for a semiconductor than for a conductor D. is high for a semiconductor than for an insulator

4.If the number of valence electrons of an atom is exactly 4, then the substance is called A. a semiconductor B. a conductor C. an insulator D. a cryogenic conductor

401. Where does practically all of the RF current flow in a conductor? A. along the surface B. in the center of the conductor C. in the electromagnetic field in the conductor center D. in the magnetic field around the conductor

403. Why is the resistance of a conductor different for RF current than for DC? A. Because of skin effect B. Because conductors are non-linear devices C. Because the insulation conducts current at radio frequency D. Because of the Heisenberg effect

414. The space outside or surrounding an electric charge where it has a force of attraction or repulsion. A. Electric field B. Magnetic field C. Electromagnetic field D. Electric flux

421. Find the dielectric constant of air. A. approximately 1 B. approximately 0 C. approximately 2 D. approximately 4

422. Electric field intensity is measured in terms of A. Volts/meter B. Newtons/meter C. Watts/meter D. Amperes/meter

424. Electric flux is a/an ________ quantity. A. scalar B. vector C. absolute D. relative

430. The absolute permittivity of air or free space. A. 1/36π x 10^-9 F/m B. 36π x 10^-9 F/m C. 1/36π x 10^-19 F/m D. 36π x 10^-19 F/m

435. Relative permittivity is also known as A. dielectric constant B. dielectric strength C. isolation strength D. permeability

440. The force between two electrically charged body is A. directly proportional to the charge B. inversely proportional to the charge C. not affected by the charge D. universally constant

447. Determine the magnitude of the electric field inside a sphere that encloses a net charge of 2 μC. A. 0 (zero) B. 9 x 10^7 N/C C. 1.8 x 10^8 N/C D. infinite

450. A charged body in free space produces 10-V potential at a distance 25 cm away. What will be the potential at 50 cm away? A. 5.0 Volts B. 7.5 Volts C. 10.0 Volts D. 15.0 Volts

453. A substance that attracts pieces iron is known as A. magnet B. conductor C. ferrite D. superconductor

458. Is believed to be the pole where the magnetic lines of force are originating. A. North Pole B. South Pole C. Unit Pole D. Universal Pole

462. A force which causes a substance to become a magnet. A. magnetizing force B. magnetomotive C. creative force D. electromagnetic force

464. Is the property of magnetic materials, which retain magnetism after the withdrawal of magnetizing force. A. retentivity B. permeability C. reluctivity D. susceptability

466. Which of the materials below that can be easily magnetized? A. soft magnetic materials B. hard magnetic materials C. low conductive materials D. high conductive materials

467. Materials that can be easily magnetized in both directions A. soft magnetic materials B. hard magnetic materials C. diamagnetic D. paramagnetic

470. The permeability of free space. A. 4π x 10^-7 H/m B. 12.56 x 10^-7 F/m C. 8.854 x 10^-7 H/m D. 8.854 x 10^-12 F/m

473. Materials with permeability slightly less than that of free space. A. diamagnetic B. paramagnetic C. ferromagnetic D. antimagnetic

476. What is the relative permeability of paramagnetic substance? A. slightly greater than 1 B. very much greater than 1 C. slightly less than 1 D. very much smaller than 1

480. Hydrogen is an example of a _________ material. A. diamagnetic B. ferromagnetic C. paramagnetic D. magnetic

482. The space outside a magnet where its poles has a force of attraction or repulsion on another magnetic pole. A. magnetic field B. magnetic flux C. magnetic flux density D. magnetic lines of force

489. What is the unit of magnetic flux in SI system? A. Weber B. Maxwell C. Tesla D. Gauss

491. A magnetic flux of 25,000 Maxwell in an area of 5 sq. cm. results in flux density of A. 5,000 Gauss (G) B. 125,000 G C. 5,000 Tesla (T) D. 125,000 T

499. Unit of permeability A. Henry/meter (H/m) B. Farad/meter (F/m) C. Henry-meter (H-m) D. Farad-meter (F-m)

5.What is the cgs unit of magnetomotive force? A. Gilbert B. Ampere- turn C. Maxwell D. Weber

501. Magnetic intensity is A. a vector quantity B. a scalar quantity C. an imaginary quantity D. either a vector or scalar

504. One Weber is equivalent to A. 10^8 Maxwells B. 10^6 Maxwells C. 10^4 Maxwells D. 10^2 Maxwells

515. Permeance is analogous to A. conductance B. resistance C. impedance D. elastance

519. The Oersted (Oe) is the same as A. 1 Gb/cm B. 1 Gb/m C. 10 Gb/cm D. 10 Gb/cm

527. The current needed for a coil of 200 turns to provide a 400 ampere turn magnetizing force is A. 2 A B. 4 A C. 6 A D. 8 A

534. The amount of magnetic field needed to remove residual magnetism from a transformer core during each half cycle is called the A. coercive force B. residual field C. hysteresis field D. demagnetizing force

535. If a wire coil has 100 turns and carries 1.3 A of current, calculate the magnetomotive force in Gilbert. A. 163.3 B. 16.33 C. 1.633 D. 0.1633

539. What is a magnetic field? A. A force set up when current flows through a conductor. B. A force set up when a charged body is at static. C. The space between two electrically charged particles. D. The space around a conductor.

540. Which of the following determines the strength of a magnetic field around a conductor? A. amount of current B. diameter of the conductor C. length of the conductor D. amount of voltage

542. In what direction is the magnetic field about a conductor when current is flowing? A. In a direction determined by the left-hand rule. B. Always in a clock wise direction. C. Always in a counter clockwise direction. D. In a direction determined by the right-hand screw rule.

543. If the electrical current carried by each of the two long parallel wire is doubled, and their separation is also doubled, the force between them A. also doubles B. increases by a factor of four C. decreases by a factor of four D. decreases by a factor of two

544. Reversing the flow of current in a circuit A. reverses the magnetic polarity B. increase the magnetic field intensity C. decreases the magnetic intensity D. enhances hysteresis

546. What law that describes the force of attraction or repulsion between two magnetic poles is directly proportional to their strengths? A. Coulomb's first law B. Coulomb's second law C. Ampere's law D. Gauss' law

548. The physical motion resulting from the forces of magnetic fields. A. motor action B. linear motion C. rectilinear motion D. generator action

6. 0ne coulomb of charge consists of electrons. A. 6 4 X 10"16 B. 62.4 x 10A16 C. 6.24 x 10A16 D. 0.624 x 10A16

7.Mmf in a magnetic circuit corresponds to in an electric circuit A. Emf B. Voltage drop C. Electric Field Intensity D. Potential gradient

A commercial alloy of aluminum nickel, and iron with cobalt, copper and titanium added to produce about 12 grades. A. Alnico B. Brass C. Aluminum D. Constantan

A current if flowing east along a power line. If the earth's field is neglected, the direction of the magnetic field below it is A. North B. South C. East D. West

A good conductor has how many valence electrons? A. 1 B. 4 C. 2 D. 8

A magnetic circuit carries a flux cpi in the iron part and a flux cpg in the air gap. What is the leakage coefficient? A. 'PiI 'Pg B. cpi X cpg C. cpg /cpi D. cpi + cpg

A magnetic material losses its ferromagnetic properties at a point called A. Curie temperature B. Inferred absolute temperature C. Room temperature D. Absolute temperature

A magnetic pole produces 5000 field lines. How much is the flux in webers? A. 50 X 10"-6 B. 5 x 10A-6 C. 500 x 10A6 D. 500 x 10A-5

A magnetizing force of 1000 AT/m will produce a flux density of in air. A. 1.257 mWb/m"2 B. 0.63 Wb/m"2 C. 1.257 Wb/m"2 D. 0.63 mWb/m"2

A negative ion results when an atom gains an additional A. Electron B. Proton C. Neutron D. Atom

A positively charged body has A. deficit of electrons B. excess of neutrons C. excess of electrons D. deficit of protons

All magnetic field originates from A. moving electric charge B. Iron atoms C. Magnetic domain D. Permanent magnet

An electron- volt (eV) is a unit of A. Energy B. Potential difference C. Charge D. Momentum

Calculate the permeability (in T/A. t/m) of a magnetic material that has a relative permeability of 300 A. 3.78 x 10"-4 B. 3.78 x 10'-5 C. 3.78 x 10'-3 D. 3.78 x 10'-6

Defined as the ratio of the volume occupied by the atoms or ions in a unit cell divided by the volume of the unit cell and is used to measure the compactness of a crystal. A. Atomic packing factor (APF) B. Ionic Packing Ratio (IPR) C. Atomic compacting factor (ACF) D. Ionic compacting ratio (ICR)

Electric potential is a quantity. A. scalar B. phasor C. vector D. variable

Electromotive force in a circuit A. causes free electrons to flow B. increases the circuit resistance C. maintains circuit resistance D. is needed to make the circuit complete

Electron is a Greek word for A. amber B. Fire C. Stone D. Heat

Electronic current in a wire is the flow of electrons. A.free B. valence C. bound D. loose

Germanium atom has protons and electrons. A. 32, 32 B. 32, 42 C. 42, 32 D. 34, 34

Hipernik is an alloy containing iron and nickel. A. 40% ; 60% B. 60% ; 40% C. 50% ; 50% D. 70% ; 30%

How many electrons are needed in the valence orbit to give a material's stability? A. 8 B. 4 C. 6 D. 5

How much is the flux in Weber in the above problem? A. 2 x 10"-5 B. 2 x 10'- 3 C. 2 x 10' D. 2 x 10'3

If a magnetic flux cuts across 200 turns at a rate of 2Wb/s, the induced voltage according to Faraday's law is about A. 400 V B. 100 V C. 200 V D. 600 V

If the number of valence electrons of an atom is less than 4, the substance is called A. a conductor B. a semiconductor C. an insulator D. a superconductor

If the number of valence electrons of an atom is less than 4, then the substance is probably A. a metal B. an insulator C. a non-metal D. a semiconductor

If the value of a25 of a conductor is 1/230 per o C, then the value of a0 is A. 1/180 per oC B. 1/150 per oC C. 1/280 per oC D. 1/230 per oC

In electro-mechanical conversion devices like generators and motors the reason whya small air gap is left between the rotor and stator is to A. permit mechanical clearance B. increase flux density in air gap C. decrease the reluctance of magnetic path D. complete the magnetic path

Materials whose permeabilities are slightly greater than that of free space A. Paramagnetic B. Non- magnetic C. Ferromagnetic D. Diamagnetic

One oersted (Oe) is equivalent to Gb/cm. A. 1 B. 10 C. 100 D. 1000

One of the solid structures in which the position of the atoms or ions are predetermined A. Crystalline solid B. Amorphous solid C. Polycrystalline solid D. Poly- amorphous solid

Permeability means A. The conductivity of the material for magnetic lines of force B. The magnetization test in the material after exciting field has been removed C. The strength of an electromagnet D. The strength of the permanent magnet

Permeance is analogous to A. Conductance B. Reluctance C. Admittance D. Resistance

Permeance of a magnetic circuit is the cross-sectional area of the circuit. A. directly proportional to B. inversely proportional to C. dependent of D. independent of

Refers to the magnetic lines A. Flux B. Hysteresis C. Current D. Magnetomotive force

Refers to the non- metallic materials that have the ferromagnetic properties of iron. A. Ferrites B. Ferromagnetic C. Diamagnetic D. Paramagnetic

Steel is hard to magnetize because of its A. Low permeability B. High permeability C. High density D. High retentivity

Temporary magnets are commonly employed in A. electric instruments B. motors C. moving coils loudspeakers D. magnetos

The air space between poles of magnets A. Air gap B. Free space C. Vacuum D. Atmosphere

The conduction of electricity across the surface of a dielectric is called A. creepage B. skin effect C. surface effect D. crosstalk

The dielectric constant of most materials lies between A. 1 and 10 B. 10 and 20 C. 20 and 50 D. 50 and 100

The emf induced in a coil due to the changing current of another neighboring coil is called A. Mutually induced emf B. Self induced emf C. Statically induced emf D. Dynamically induced emf

The emf produced in a wire by its motion across a magnetic field does not depend upon the A. Diameter of the wire B. Length of the wire C. Orientation of the wire D. Flux density of the field

The force acting on a pole of 5 Wb is 25 N. What is the intensity of the magnetic field? A. 5 N B. 25 N/Wb C. 125 N/Wb D. 0.2 N/Wb

The force acting on a unit n- pole placed at that point is called A. Magnetic field intensity B. Electric field intensity C. Electromagnetic field intensity D. Intensity magnetization

The hot resistance of an incandescent lamp is about its cold resistance. A. 10 times B. 100 times C. 5 times D. 50 times

The induced emf in a wire loop that is moved parallel to a uniform magnetic field is A. Zero B. Dependent on the area of the loop C. Dependent on the shape of the loop D. Dependent on the magnitude of the field

The magnetic field of a magnetized iron bar when strongly heated A. Becomes weaker B. Becomes stronger C. Reverses in direction D. is unchanged

The magnetic flux through a coil changes. This results to the induced emf acting in a direction as to A. Oppose the change B. Aid the change C. Either oppose or aid the change D. Neither oppose nor aid the change

The magnetic potential in a magnetic circuit can be measured in terms of A. Mmf B. Emf C. Farad D. Coulomb

The net electrical charge in an isolated system remains constant. This is known as A. Law of conservation of charge B. Coulomb's first law C. Coulomb's second law D. Law of conservation of energy

The phenomenon by which a subtracts pieces of iron A. Magnetism B. Electromagnetism C. Naturalism D. Materialism

The phenomenon that when an electric current passes through an anisotropic crystal, there is an absorption or liberation of heat due to the non-uniformity in current distribution. A. Bridgman effect B. Corona effect C. Dember effect D. Destriau effect

The physical motion resulting from the forces of magnetic fields is called A. Motor action B. Rotation C. Repulsion D. Torque action

The point in a magnet where the intensity of magnetic lines of force is maximum A. Magnetic pole B. South pole C. North pole D. Unit pole

The potential at a point due to a charge is 15 V. If the distance is increased three times, the potential at the point will be A. 5 V B. 18 V C. 45 V D. 15 V

The process by which an emf and hence current is generated or induced in a conductor when there is a change in the magnetic flux linking the conductor is called A.Electromagnetic induction B. Mutual induction C. Faraday's law D. Electromagnetic interference

The property of magnetic materials of retaining magnetism after withdrawal of the magnetizing force is known as A. Retentivity B. Reluctivity C. Resistivity D. Conductivity

The quantity 10'8 maxwells is equivalent to one A. Weber B. Gauss C. Gilbert D. Tesla

The ratio of the permeability of material to the permiabiity of air or vacuum. A. Relative permeability B. Relative permittivity C. Relative conductivity D. Relative reluctivity

The space outside the magnet where its pole have a force of attraction or repulsion on a magnetic pole is called A. Magnetic field B. Electric field C. Electromagnetic field D. Free Space Field

The temperature coefficient of resistance of conductors is A. positive B. zero C. negative D. infinite

The tiniest element of matter A. Atom B. Proton C. Electron D. Neutron

The total number of magnetic lines of force in a magnetic field is called A. Magnetic flux B. Magnetic flux density C. Magnetic flux intensity D. Magnetic potential

Theory of ferromagnetic phenomena which assumes each atom is a permanent magnet which can turn freely about its center under the influence of applied field and other magnets. A. Ewing's theory of ferromagnetism B. Oersted's ferromagnetism theory C. Maxwell's magnetic theory D. Ampere's circuital law

This paper does not exhibit electricity because it contains the same number of A. protons and electrons B. neutrons and electrons C. neutrons and positrons D. atoms

Three charges of +5 C, -6 C and +9 C are placed inside a sphere. What is the total flux passing through the surface of sphere? A. 8 C B. 14 C C. 20 C D. -6 C

Two similar poles, each 1Wb, placed 1 m apart in air will experience a repulsive force of A. 63000 N B. 63 x 1 -3 N C. 8 x 1 12 N D. 796 kN

What bond is formed when one or more electrons in the outermost energy orbit of an atom are transferred to another? A. Ionic B. Covalent C. Metallic D. Van der Waals

What determines the atomic number of an element? A. The number of protons B. The number of electrons C. The number of neutrons D. The number of neutrons and protons

What is the SI unit of conductance? A. Siemens B. Mhos C. Ohms D. 1/Ohms

What is the SI unit of specific resistance or resistivity? A. Ohm-circular mil per inch B. Ohm-circular mil per foot C. Ohm-m D. Ohm-cm

What is the diameter of an atom? A. About 10"-10 m B. About 10"-10 cm C. About 10"-10 mm D. About 10"-10 µm

What is the main advantage of temporary magnets? A. The magnetic flux can be changed. B. Hysteresis can be decreased. C. Magnetic materials can be used. D. Abundance of ferromagnetic material that can be temporarily magnetized

What is the measure of the density and sign of the electric charge at a point relative to that at sometime? A. Electric potential B. Electric charge C. Electric current D. Electric intensity

What is the other name for dielectric strength? A. Breakdown voltage B. Electric intensity C. Potential gradient D. Dielectric constant

What is the reluctance of a magnetic path having a length of 2x 10'-3m and crosssectional area of 2.5 x 10'-3 m'2? A. 6366 A.t/Wb B. 6000 A.t/Wb C. 8x10'-3 A.t/Wb D. 0.8 A.t/Wb

When a conductor is stationary and the magnetic field is moving or changing the emf induced is called A. Statically induced emf B. Mutually induced emf C. Self induced emf D. Dynamically induced emf

When the relative permeability of a material is slightly less than 1, it is called material. A. diamagnetic B. ferromagnetic C. paramagnetic D. non-magnetic

Which of the following electric quantities is vector in character? A. Field B. Charge C. Energy D. Potential Difference

Which of the following has the least number of valence electrons? A. Conductor B. Semiconductor C. Insulator D. Semi- insulator

Which of the following magnetic materials can be easily magnetized in both direction? A. Soft magnetic materials B. Hard magnetic materials C. High hysteresis loss materials D. Low hysteresis loss materials

Which of the following materials has the highest dielectric strength? A. Glass B. Oiled paper C. Mica D. Air

Who demonstrated the theory of electromagnetic induction in 1831? A. Michael Faraday B. Andre Ampere C. James Clerk Maxwell D. Charles Coulomb

Who discovered superconductivity in 1911? A. Kamerlingh Onnes B. Alex Muller C. Geory Bednorz D. Charles Coulomb

Who discovered that a current-carrying conductor would move when placed in a magnetic field? A. Michael Faraday B. Andre Ampere C. Hans Christian Oersted D. Gustav Robert Kirchhoff

Who discovered the most important electrical effects which is the magnetic effect? A. Hans Christian Oersted B. Sir Charles Wheatstone C. Georg Ohm D. James Clerk Maxwell

. Hydrogen is an example of a material. A. Paramagneti c B. Diamagnetic C. Ferromagnetic D. Non- magnetic

. If the value of a0 a conductor is 1/234 per o C, then the value of a18 is A. 1/218 per oC B. 1/252 per oC C. 1/272 per oC D. 1/273 per oC

. Referred to as the specific reluctance of a material A. Resistivity B. Reluctivity C. Conductivity D. Permeability

.A one cubic cm of copper has how many free electrons at room temperature? A. 80 x 10A18 B. X 10" C. 20 x 10A10 D. 50 x 10A20

.Hysteresis loss can be reduced by one of the following. A. Increasing mmf of the circuit B. Using material narrow hysteresisloop C. Using ferromagnetic core D. Laminating the magnetic circuit

.The temperature coefficient of resistance of a conductor with an increase in temperature. A. increases B. decreases C. remains the same D. becomes negative

214. The reciprocal of reluctance A. conductance B. permeance C. elastance D. capacitance

308. Approximate diameter of a Hydrogen atom A. 1.1 x 10^-10 µµm B. 1.1 x 10^-10 µm C. 1.1 x 10^-10 mm D. 1.1 x 10^-10 m

315. The mass of a proton is approximately A. 1.6726 x 10^-19 Kg B. 1.6726 x 10^-27 Kg C. 1.6022 x 10^-19 Kg D. 1.6022 x 10^-27 Kg

331. Electrons at the outermost shell are called A. free electrons B. valence electrons C. deep state electrons D. shallow state electrons

336. Materials that might have eight valence electrons A. conductor B. insulator C. semiconductor D. semi-insulator

339. Determine which statement is true? A. The current carriers in conductors are protons. B. The current carriers in conductors are valence electrons. C. Valence and inner electrons are the carriers in conductors. D. Valence electrons are not the ones that become free electrons.

349. A factor that does not affect the resistance of the material. A. atomic structure B. mass C. length D. cross-sectional area

355. Refers to the lowest voltage across any insulator that can cause current flow. A. conduction voltage B. breakdown voltage C. voltage flow D. voltage drop

357. When all atoms of a molecule are the same, the substance is called A. a crystal B. an element C. a compound D. an ion

359. Isotope means, the same element but with different number of A. electrons B. neutrons C. protons D. atoms

372. What do you call a negatively charged ion? A. electron B. anion C. cation D. domain

376. Gases with charged particles. A. inert B. plasma C. conductive D. reactive

382. The net movement of charged particles in one direction or another. A. flow B. current C. drift current D. diffusion current

390. The greater the diameter of a wire, the _______ is the resistance. A. greater B. lesser C. harder D. bigger

394. The area of a conductor whose diameter is 0.001 inch is equal to A. one angstrom B. one circular mil C. one micron D. one steradian

406. Electron volt (eV) is a unit of A. power B. energy C. magnetic field D. magnetic force

411. Test charge has a charge of A. 0 Coulomb B. +1 Coulomb C. -1 Coulomb D. Infinity

418. What do you call the total number of electric lines of force in an electric field? A. Electric field B. Electric flux C. Electric flux density D. Electric lines of force

423. Electric field intensity is A. a scalar quantity B. a vector quantity C. an absolute value D. a relative value

425. Electric flux density is a/an ________ quantity. A. scalar B. vector C. absolute D. relative

426. Three charges of +5 C, -6 C, and +7 C are inside a sphere, what is the total electric flux passing through the surface of the sphere? A. 5 Coulombs B. 6 Coulombs C. 7 Coulombs D. 8 Coulombs

431. The relative permittivity of air. A. 0 B. 1 C. 1/36π x 10^-9 F/m D. 8.854 x 10^-12 F/m

432. Calculate the permittivity of a material with relative permittivity of 5. A. 8.854 x 10^-11 F/m B. 4.42 x 10^-11 F/m C. 1/36π x 10^-9 F/m D. 8.854 x 10^-12 F/m

434. How does permittivity affect electric field intensity? A. It causes the field intensity to increase. B. It causes the field intensity to decrease. C. It causes the field intensity to fluctuate up and down. D. It has no effect on field intensity.

436. Most materials' relative permittivity lies between A. 0.01 - 1 B. 1 - 10 C. 10 - 50 D. 50 - 100

437. Charge body at rest is said to exhibit electric field, which interacts with other bodies. The study of this phenomena is known as A. electricity B. electrostatics C. electromagnetism D. field interactions

439. The force between the two electrically charged body is called A. electromotive force B. electrostatic force C. electromagnetic force D. magnetic force

442. Determine the force in Newton between 4μC charges separated by 0.1 meter in air. A. 1.44 N B. 14.4 N C. 144 N D. 1440 N

444. The value of k in Coulomb's electrostatic force equation ( F = kQ1Q2/r^2 ) is oftentimes expressed as 1/4πεο. What is εο? A. absolute permeability B. absolute permittivity C. relative permeability D. relative permittivity

451. What do you call the phenomenon whereby substance attracts pieces of iron? A. Permeability B. Magnetism C. Naturalism D. Electromagnetism

459. What do you call a pole that when place in air with a similar and equal pole will cause a force of repulsion of 1/4πμο Newtons? A. South Pole B. Unit pole C. Convergence pole D. Universal Pole

461. The phenomenon in which a substance becomes a magnet when placed near a magnet. A. magnetic transfer B. magnetic induction C. electromagnetism D. magnetism

468. Ability of a material to conduct magnetic flux through it refers to A. permittivity B. permeability C. reluctivity D. conductivity

469. The ability to concentrate magnetic lines of force. A. retentivity B. permeability C. susceptability D. reluctivity

471. The ratio of material permeability to the permeability of air or vacuum. A. relative conductivity B. relative permeability C. inverse permeability D. inverse permittivity

472. What is the relative permeability of air? A. 0 B. 1 C. 4π x 10^-7 H/m D. 8.854 x 10^-12 F/m

474. Materials with permeability slightly greater than that of free space. A. diamagnetic B. paramagnetic C. ferromagnetic D. antimagnetic

478. Nonmetallic materials that has ferromagnetic properties. A. termites B. ferrites C. ferrous D. loadstone

481. Cobalt is an example of a _________ material. A. diamagnetic B. ferromagnetic C. paramagnetic D. magnetic

484. What do you call the total number of magnetic lines of force in a magnetic field? A. magnetic field B. magnetic flux C. magnetic flux density D. magnetic lines of force

492. Calculate the flux density in Gauss (G) having a flux of 12,000 Mx through a perpendicular area of 6cm. A. 200 G B. 2,000 G C. 7,200 G D. 72,000 G

494. The capacity of a substance to become magnetized. This is expressed as a ratio between the magnetization produced in a substance to the magnetizing force producing it. A. magnetic conductivity B. magnetic susceptibility C. magnetic resistivity D. magnetic reluctivity

495. The typical saturation flux density for most magnetic materials. A. 0.1 Wb/m^2 B. 2 Wb/m^2 C. 10 Wb/m^2 D. 20 Wb/m^2

496. The force between two magnetic poles is _________ permeability of the medium. A. directly proportional to the B. inversely proportional to the C. not dependent of the D. exponentially proportional to the

498. A force of 20 N is acting on a 10 Wb magnetic pole, calculate the intensity of the magnetic field? A. 0.5 N/Wb B. 2 N/Wb C. 10 N/Wb D. 20 N/Wb

500. The unit of permittivity A. Henry/meter (H/m) B. Farad/meter (F/m) C. Henry-meter (H-m) D. Farad-meter (F-m)

505. The equivalent of 1 x 10^9 Maxwells is A. 1 Weber B. 10 Weber C. 100 Weber D. 1,000 Weber

507. The unit of flux density in mks A. Gauss B. Weber/m^2 C. Maxwell D. Tesla

509. Voltage in electrical circuits is analogous to _________ in magnetic circuits. A. Ampere-turn B. Magnetomotive force C. Magnetizing force D. Flux

511. __________ capability is analogous to permeance. A. Admittance B. Conductance C. Reluctance D. Resistance

516. Is the reciprocal of reluctance and implies the readiness of a material to develop magnetic flux. A. elastance B. permeance C. susceptance D. conductance

517. Magnetic circuit property that permits flux. A. elastance B. permeance C. susceptance D. conductance

525. One Gilbert is equal to A. 0.0796 At B. 0.796 At C. 7.96 At D. 79.6 At

526. One Ampere-turn (At) is equivalent to A. 0.126 Gilbert B. 1.260 Gilberts C. 12.60 Gilberts D. 126 Gilberts

528. Determine the ampere-turns when a 10 V battery is connected across a solenoid having 100 turns and a resistance of 5 Ω. A. 50 At B. 200 At C. 100 At D. 1,000 At

529. What is residual magnetism? A. The external magnetic field when the current is flowing through the exciting coil. B. The flux density, which exist in the iron core when the magnetic field intensity is reduced to zero. C. The flux density, which exist in the iron core when the magnetic field intensity is at its maximum value. D. The flux density when the magnetic core is saturated.

538. Magnetic flux can always be attributed to A. static charged particles B. motion of charge particles C. static electric field D. every applied potential

541. The magnetic flux around a straight, current carrying wire, is stronger A. near the edge B. near the wire C. at the center D. at both edge

547. What is the law whereby the force of attraction or repulsion between poles is inversely proportional to the square of the distance between them? A. Coulomb's first law B. Coulomb's second law C. Coulomb's third law D. Coulomb's law

550. A changing magnetic field A. produces an electric field B. induces potential C. produces a fluctuating electric field D. produces a steady electric field

6. If the resistance of a material 2 m long and 2 mA2 in area of cross-section is 1.6 x10A8 n, then its resistivity is A. 3.2 x 10A-8 n-m B. 1.6 x 10"-8 0-m C. 0.64 x 10A-8 nm D. 0.16 x 10A-8 n-m

7. If two similar charges 1 coulomb each are placed 1 m apart in air, then the force of repulsion is A.8 x 10A6 N B. 9 x 1 "9 N C. 10A6 N D. 5 x 10A6 N

9.The direction of force o a current carrying conductor placed in a magnetic field can be found by A. Cork screw rule B. Fleming's left hand rule C. Fleming's right hand rule D. using a compass

A 200-watt lamp working for 24 hours will consume approximately units. A. 50 B. 5 C. 24 D. 0.5

A germanium atom has an atomic weight of 72. How many neutrons are there? A. 32 B. 40 C. 34 D. 36

A magnetic field is A. The current flow through space around a permanent magnet B. The force set up when current flows through a conductor C. The force that drives current through a resistor D. The force between the plates of a charged capacitor

A magnetic flux of 2.5 x10'4 Wb through an area of 5 x10'4 square meters results in A. 5 Wb B. 0.5 Tesia of flux density C. 5x 10'-5 Wb of flux D. 5000 Tesia of flux density

A principle that states that only two electrons with different spins are allowed to exist in a given orbit A. Bohr's principle B. Pauli exclusion principle C. Avogadro's principle D. Coulomb's principle

Amorphous solid is also called A. Crystalline B. Non- crystalline C. Polycrystalline D. Homogenous

At/m is a unit of A. mmf B. magnetic force C. reluctance D. magnetic flux density

Core materials of a good relay have hysteresis loop. A. large B. narrow C. very large D. very narrow

Defined as a closed path in which magnetic induction or flux flows A. Electric circuit B. Magnetic circuit C. Electronic circuit D. Electromagnetic circuit

If the distance between two magnetic poles decreases by 2 times, the force between them A. decreases two times B. increases four times C. increases two times D. decreases four times

If the solenoid is gripped by the right hand with the fingers pointing the direction of current flow, the outstretched thumb will then point the north pole. This is known as A. Right hand rule B. Helix rule C. End rule D. Cork screw rule

If the value of a25 a conductor is 1/255 per o C, then the value of a20 is A. 1/300 per oC B. 1/250 per oC C. 1/230 per oC D. 1/260 per oC

One ampere- turn is equivalent to gilberts A. 1.16 B. 1.26 C. 1.36 D. 1.46

One that has magnetic poles produced by internal atomic structure with no external current necessary A. Diamagnetic B. Permanent magnets C. Paramagnetic D. Electromagnetic

Permanent magnets can be found in A. electric bells B. earphones C. relays D. dynamic loudspeakers

Residual magnetism refers to the flux density, which exists in the iron core when the magnetic field intensity is A. Minimized B. Reduced to zero C. Maximize D. Unity

Temporary magnets are commonly employed in A. electric instruments B. motors C. moving coils loudspeakers D. magnetos

The B-H curve for is a straight line passing through the origin. A. cobal t B. air C. hardened steel D. soft iron

The K shell or the first shell has how many permissible number of orbiting electrons? A. I B. 2 C. 3 D. 4

The branch of Engineering which deals with the magnetic effect of electric current is known as A. Magnetism B. Electromagnetism C. Electrical engineering D. Electronics engineering

The contribution to the ionization in an ionization chamber by electrons liberated from the walls. A. Skin effect B. Walt effect C. Hall effect D. Edison effect

The current of electric circuit is analogous to which quantity of a magnetic circuit A. Mmf B. Flux C. Flux density D. Reluctivity

The electric flux density is a quantity. C. 90 o A. phasor B. vector C. scalar D. variable

The electric potential across part AB of a circuit is 5 V; point A being at higher potential. If a charge of 5 C moves from A to B, then energy released as A. 5 joules B. 25 joules C. 10 joules D. 100 joules

The electrons in the last orbit of an atom are called ------- electrons. A. free B. valence C. bound D. thermionic

The emission of electrons from hot bodies is called A. Radiation effect B. Edison effect C. Skin effect D. Half effect

The force between two charges placed a given distance apart as the relative permittivity of the medium is increased. A. increases B. decreases C. remains unchanged D. becomes infinite

The force between two magnetic poles is their polesstrength. A. equal to B. directly proportionalto C. inversely proportional to D. directly proportional to the square root of

The greater percentage of materials is . A. diamagnetic B. paramagnetic C. ferromagnetic D. non-magnetic

The magnetic field around the conductor is determined by the A. Size of the conductor B. Amount of current C. Current divided by the resistance D. Resistance divided by the current

The magnetic field inside a solenoid A. is zero B. is uniform C. increases with distance from the axis D. decreases with distance from the axis

The magnetic flux of 2000 lines is how many Maxwells? A. 1000 B. 2000 C. 4000 D. 8000

The magnitude of the induced emf in a coil is directly proportional to the rate of change of flux linkages. This is known as A. Joule's Law B. Faraday's second law of electromagnetic induction C. Faraday's first law of electromagnetic induction D. Coulomb's Law

The mass of proton is the mass of an electron. A. equal to B. about 1837 times C. less than D. 200 times

The permeability of a material having a flux density of 5 Wb/mA2 is 10A-5 H/m. What is the value of magnetizing force? A. 5 x 10A-5 N/Wb B. 500 X 10"3 N/Wb C. 4n x 10A-7 N/Wb D. 4n x 10A7 N/Wb

The property of a material which opposes the creation of magnetic flux in it A. Resistance B. Reluctance C. Permeance D. Conductance

The reluctance of the magnetic circuit is _ relative permeability of the material comprising the circuit. A. directly proportional to B. inversely proportional to C. independent of D. dependent of

The simplest type of atom to exist is the atom. A. Helium B. Hydrogen C. Boron D. Oxygen

The temperature coefficient of resistance of insulators is A. zero B. negative C. positive D. infinite

The unit of flux density is A. Wb/m B. Tesla C. At/m D. N/Wb

Under ordinary conditions, a body is considered A. positively charged B. neutral C. negatively charged D. stable

What bond is formed when electrons in the outermost energy orbits of the atoms are shared between two or more electrons? A. Ionic B. Covalent C. Metallic D. Van der Waals

What is the SI unit of magnetic flux? A. Tesla B. Weber C. Maxwell D. Gauss

What is the practical unit of electrical energy? A. Watt B. Kilowatt-hour C. Kilowatt-second D. Megawat-hour

What is the relative permittivity of air? A. 0 B. 1 C. 8.854 x 10A12 D. 41 x 10A-7

What is used as the insulating material or dielectric in an electric ion? A. Oiled paper B. Mica C. Paraffin D. Titanate compound

What principle states that each electron in an atom must have a different set of quantum numbers? A. Inclusion principle B. Exclusion principle C. Quantum principle D. Electron principle

What solid has no defined crystal structure except perhaps in the arrangement of the nearest neighboring atoms or ions? A. Crystalline B. Amorphous C. Polycrystalline D. Poly- amorphous

When a wire loop is rotated in a magnetic field the direction of the induced emf changes one in every revolution A. 1/3 B. 1/2 C. 1/4 D. 2/3

When the ferromagnetic substance is inserted in a current- carrying solenoid, the magnetic field is A. Greatly decreased B. Greatly increased C. Slightly decreased D. Slightly increased

When the relative permeability of a material is much greater than 1, it is called material. A. diamagnetic B. ferromagnetic C. paramagnetic D. non-magnetic

Which of the following is a vector quantity? A. Magnetic potential B. Magnetic field intensity C. Magnetic permeability D. Flux density

Which of the following materials has the least hysteresis loop area? A. soft iron B. silicon steel C. hard steel D. wrought iron

Which of the following statements is TRUE? A. Silicon dioxide is a good B. The current carriers in conductors are valence electrons C. For conductors, the valence electron are strongly attracted to the nucleus D. The valence electrons are located in the nucleus of an atom

Who discovered the relationship between magnetism and electricity that serves as the foundation for the theory of electromagnetism? A. Luigi Galvani B. Hans Christian Oersted C. Andre Ampere D. Charles Coulomb

. An effect which is generally used in the gausameter to measure flux density. A. Skin effect B. Magnetic effect C. Hall effect D. Flywheel effect

. The electric field intensity between the parallel plate air capacitor is 20 N/C. If an insulating slab of relative permittivity 5 is placed between the plates, then electric field intensity will be A. 20 N/C B. 100 N/C C. 4 N/C D. 40 N/C

. is a substance of whose molecules consist of the same kind of atom. A. Mixture B. Compoun d C. Element D. Isotope

.A negatively charge body has A. deficit of electrons B. excess of protons C. excess of electrons D. deficit of neutrons

.An alloy of 40 percent iron and 60 percent nickel. A. Alnico B. Permallo y C. Hipernik D. Manganin

.Hysteresis is a phenomenon of in a magnetic circuit. A. setting up constant flux B. lagging of H behind B C. lagging B behind H D. leading B ahead H

.If the length and area of cross-section of a wire are doubled, then its resistance A. becomes four times B. becomes sixteen times C. remains the same D. becomes two times

.If the relative permittivity of a material is 10, then its permittivity is A. 41 x 10A-7 F/m B. 41 x 10A-6 F/m C.8.854 x 1 "-11 F/m D.8.854 x 10A-12 F/m

.Magnetic field intensity is a quantity. A. scalar B. phasor C. vector D. variable

.The relative permeability of a magnetic material is 10A5. What is its permeability? A. 4n x 10A5 H/m B. 4n x 10A-12 H/m C. 41 t x 10 - H m D. 4n x 10A-7 H/m

.The resistance of a material is its area ofcross-section. A. directly proportional B. independent of C. inversely proportionalto D. equal to

.What is the unit of magnetomotive force? A. Volt B. Tesla C. Ampere- turn D. Weber

0hm's law cannot be applied to which material? A. Copper B. Silver C. Silicon carbide D. Aluminum

1.How is mutual inductance between two coils decreased? A. By using a common core B. By moving the coils closer C. By moving the coils apart D. By increasing the number of turns of either coil

306. The lightest kind of atom or element A. Helium B. Oxygen C. Hydrogen D. Titanium

319. The discrete amount of energy required to move an electron from a lower shell to a higher shell. A. negative energy B. positive energy C. quantum D. quanta

323. In an atomic structure, what particle that has no charge and therefore has no effect on its atomic charge A. electrons B. protons C. neutrons D. nucleons

324. The atomic number of an element is determined by the number of A. electrons B. valence electrons C. protons D. protons or neutrons

326. If an element has an atomic number of 12, there are how many protons and electrons? A. 6 protons and 12 electrons B. 12 protons and 6 electrons C. 12 protons and 12 electrons D. 12 protons and 24 electrons

334. What elements possess four valence electrons? A. Insulators B. Semi-insulators C. Semiconductors D. Conductors

340. A material that contains an abundance of free carrier is called A. insulator B. semi-insulator C. conductor D. semiconductor

343. __________ has a unit of electronvolt(eV). A. Charge B. Potential difference C. Energy D. Current

346. The energy gap of an insulator is in the order of A. zero electron volt (0 eV) B. one electron volt (1 eV) C. five electron volt (5 eV) D. one-tenth electron volt (0.1 eV)

352. What will happen to an atom if an electron is either taken out or taken into the same atom? A. Becomes negative ion B. Becomes positive ion C. Becomes an ion D. Nothing will happen

353. When an atom gains an additional _________, it results to a negative ion. A. neutron B. proton C. electron D. atom

356. Dielectric is another name for A. conductor B. semiconductor C. insulator D. semi-insulator

360. The particles that make up the lattice in ionic crystal A. molecules B. ions C. electrons D. neutrons

369. A negative ion results when an atom A. loss some of its inside electrons B. loss some of its valence electrons C. gains additional electron D. gains additional proton

370. A positive ion has A. excess of electrons B. excess of neutrons C. lack of electrons D. lack of protons

371. What do you call a positively charged ion? A. cathode B. anion C. cation D. domain

373. __________ is the procedure by which an atom is given a net charge by adding or taking away electron. A. Polarization B. Irradiation C. Ionization D. Doping

381. What is the charge magnitude, Q of a body if it lacks 5 electrons? A. 5 x 10^-19 Coulomb B. 5 Coulomb C. 8 x 10^-19 Coulomb D. 19 x 10^-19 Coulomb

386. When one coulomb of electric charge continuously passes a given point every second, the electric current is said to A. 1 µA B. 1 mA C. 1 A D. 10 A

389. If in a material, current can hardly pass, it means A. the material is very hard B. the material is very soft C. the material has high resistance D. the material has less resistance

395. A 100m long wire with a cross-sectional area A=10-3 m2 has a resistance of 10Ω. Determine the resistivity of the wire. A. 10^-2 Ω-m B. 10^-3 Ω-m C. 10^-4 Ω-m D. 10^-5 Ω-m

398. What happens in the resistance of copper wire when its temperature is raised? A. decreased B. steady C. increased D. zero

402. ________ is one factor that does not affect resistance. A. Cross sectional area B. Resistivity C. Mass D. Length

405. Find the charge in coulombs of dielectric that has a positive charge of 14.5 x 10 to the 18th power protons. A. 29 x 10 to the 16th Coulombs B. 14.5 x 10 to the 16th Coulombs C. 14.5 x 10 to the 18th Coulombs D. 29 x 10 to the 18th Coulombs

419. The number of lines per unit area in a plane perpendicular to the electric lines of force. A. Electric field B. Electric flux C. Electric flux density D. Electric lines of force

429. The ability of the material to store electrical potential energy under the influence of an electric field. A. capacity B. permeability C. permittivity D. conductivity

446. Calculate the electric field intensity 10cm from a charge Q = 5nC. A. 450 N/C B. 900 N/C C. 4.5 x 10^3 N/C D. 9.0 x 10^3 N/C

448. Calculate the total electric field at the surface of a sphere of radius r = 1cm, and enclosing a net charge of 2 μC. A. 0 (zero) B. 9 x 10^7 N/C C. 1.8 x 10^8 N/C D. infinite

452. The condition in which a substance attracts pieces of iron is known as A. Electromagnetism B. Electrolysis C. Magnetism D. Magnetic Induction

454. A natural magnet A. loadstone B. carbon C. lodestone D. magnesium

455. Group of magnetically aligned atoms. A. Lattice B. Crystal C. Domain D. Range

457. Which of the following refers to a characteristic of a magnetic line of force? A. Travels from south to north through the surrounding medium of a bar magnet B. Travels back and forth between the north and south pole of a bar magnet C. Travels from north to south through the surrounding medium of a bar magnet D. Stay stationary between the north and the south of a bar magnet

465. A substance having high retentivity is best suited in making A. an electromagnet B. a temporary magnet C. a permanent magnet D. two pole magnet

475. What do you call materials, which possess very high permeabilities? A. diamagnetic B. paramagnetic C. ferromagnetic D. antimagnetic

485. The number of lines per unit area in a plane perpendicular to the magnetic lines of force. A. magnetic field B. magnetic flux C. magnetic flux density D. magnetic lines of force

486. The direction of field lines outside a magnet is A. from north to south pole B. from south to north pole C. either from north to south or south to north pole D. dependent on the magnet's orientation with respect to the earth's magnetic pole

487. The entire group of magnetic field lines flowing outward from the north pole of a magnet. A. magnetic field B. magnetic flux density C. magnetic flux D. electromagnetic field

488. Magnetic lines of force are called A. magnetic field B. magnetic flux density C. magnetic flux D. electromagnetic field

493. What does a gauss meter measure? A. flux B. magnetic field C. magnetic flux density D. mmf

503. What is the unit of flux in cgs? A. Ampere-turn (At) B. Coulomb/sec. (C/s) C. Maxwell (Mx) D. Gauss

508. What do you call the force that sets up or tends to set up magnetic flux in a magnetic circuit? A. electromotive force B. potential difference C. magnetomotive force D. dynamic force

520. The unit of reluctance A. Gilbert B. Tesla C. At/Wb D. Gauss

521. It is the specific reluctance of a material. A. resistivity B. retentivity C. reluctivity D. permeability

522. At/m is a unit of A. magnetic field B. reluctance C. magnetizing force D. magnetic power

524. The cgs unit of magnetomotive force A. Volt B. Weber C. Gilbert D. Ampere-turn

530. When you demagnetize property by applying an AC field and then gradually reduced it to zero, it is called A. damping B. decaying C. degaussing D. gaussing

537. Electromagnet whose core is in the form of a close magnetic ring A. solenoid B. relay C. toroid D. circular

549. What law in electronics where an induced current will be in such a direction that its own magnetic field will oppose the magnetic field that produces the same? A. Electromagnetic law B. Norton's law C. Lenz law D. Maxwell law

A 6- V battery is connected across a solenoid of 100 turns having a resistance of 2 n, Calculate the number of ampere turns? A. 100 B. 50 C. 300 D. 600

A group of magnetically aligned atoms is called A. Range B. Lattice C. Domain D. Crystal

A law establishing the fact that the algebraic su of the rises and drops of the mmf around a closed loop of a magnetic circuit is equal to zero. A. Kirchhoff's circuital law B. Maxwell's circuital law C. Ampere's circuital law D. Coulomb's circuital law

A law that states that the current in a thermionic diode varies directly with the three- halves power of anode voltage and inversely with the square of the distance between the electrodes, provided operating conditions are such that the current is limited only by the space charge. A. Hall's law B. Joule's law C. Child's law D. Coulomb's law

A length of wire has a resistance of 10 ohms. What is the resistance of a wire of the same material three times as long and twice the cross-sectional area? A. 30 ohms B. 20 ohms C. 15 ohms D. 7 ohms

A substance that attracts pieces iron A. Conductor B. Semiconductor C. Magnet D. All of the above

A test charge means a charge of A. -1 C B. 1 electron C. +1 C D. -20 C

An atom or a group of atoms that carries a net electric charge. A. Positive ion B. Negative ion C. Ion D. Electron

Another term for corona discharge. A. Lightning B. Sparkin g C. Aurora D. Corona Effect

As the magnetic intensity decreases, the relative permeability of a magnetic material A. decreases B. remains the same C. increases D. becomes zero

Calculate the flux density that will be produced by the field intensity of 2000 a. t/m for a permeability of 126 x 10'-6 T/A.t/m A. 0.252 G B. 0.252 x 10'-2 T C. 0.252 T D. 0.252 x 10'-2 G

Cobalt is an example of a material. A. Paramagnetic B. Diamagnetic C. Ferromagnetic D. Non- magnetic

Define as that pole which when placed in air from a similar and equal pole repels it with a force of newtons A. North pole B. South pole C. Unit pole D. Magnetic pole

Defined as the number of lines per unit area through any substance in a plane at right angles to the lines of force A. Flux B. Flux lines C. Flux density D. Flux intensity

Electric field intensity at a point due to a given charge if the relative permittivity of the medium decreases. A. decreases B. remains unchanged C. increases D. becomes zero

Electric field intensity is a . A. scalar B. phasor C. vector D. variable

Electric lines of force leave or enter the charge surface at an angle of A. 30o B. 45 o C. 90 o D. depending upon the angle of launch and entry

How many neutrons does a copper atom have? A. 32 B. 33 C. 34 D. 29

How many turns are needed to produce a magnetomotive force of 1000 A.t for a coil with 6 amperes? A. 6000 turns B. 600 turns C. 167 turns D. 67 turns

If the number of valence electrons of an atom is more than 4, the substance is called A. a semiconductor B. a conductor C. an insulator D. a semi-insulator

If the right handed bottle-opener cork screw is assumed to be along the conductor so as to advance in the direction of current flow, the motion of its handle will indicate the direction of magnetic flux produced around the conductor. This is known as A. Right hand rule B. Left hand rule C. Cork screw rule D. End rule

It is the reciprocal of reluctance and implies the case of readiness with which magnetic flux is developed. A. Resistance B. Conductanc e C. Permeance D. Inductance

Magnetic effects of the earth as a huge magnet with north and south poles. A. Diamagnetic B. Ferromagnetic C. Terrestrial magnetism D. Terrestrial ferromagnetism

Materials that have very high permeabilities (hundreds and even thousands times of that of free space) A. Paramagnetic B. Non- magnetic C. Ferromagnetic D. Diamagnetic

Paramagnetic substance has a relative permeability of A. Slightly less than one B. Equal to one C. Slightly equal to one D. Very much greater than one

Small voltages generated by a conductor with current in an external magnetic field. A. Skin effect B. Magnetic effect C. Hall effect D. Flywheel Effect

The ability of a mechanically stressed ferromagnetic wire to recognize rapid switching of magnetization when subjected to a dc magnetic field. A. Wartheim effect B. Wiedemann effect C. Wiegand effect D. Edison effect

The amount of magnetizing force to counter balance the residual magnetism of a magnetic material is referred to as A. Reluctivity B. Susceptivity C. Coercivity D. Retentivity

The customary energy unit in atomic and nuclear physics is A. Joule B. Voltcoulomb C. electron-volt D. Walt- second

The diameter of a hydrogen atom is approximately cm. A. 1.1 x 1Q'-6 B. 1.1 x 1Q'-7 C. 1.1 x 10"-8 D. 1.1 x 1Q'-9

The electric potential at a point in air due to a charge is 21 V. If the air is replaced by a medium of relative permittivity of 3, then electric potential at that point will be A. 63 V B. 21 V C. 7 V D. 42 V

The energy stored in an electrostatic field or electromagnetic field is called A. Electromagnetic energy B. Kinetic energy C. Potential energy D. Rest energy

The evaporation of electrons from a heated surface is called A. Radiation B. Convection C. Thermionic emission D. Conduction

The force between two magnetic poles is the relative permeability of the medium. A. directly proportional to B. independent of C. inversely proportionalto D. equal to

The force of attraction or repulsion between two magnetic poles is directly proportional to their strengths. A. Newton's first law B. Faraday's first law of electromagnetic induction C. Coulomb's first law D. Coulomb's second law

The idea of preventing one component from affecting another through their common electric and magnetic field is referred to as A. Hall effect B. Groundin g C. Shielding D. Limiting

The lagging effect between flux density of the material and the magnetizing force applied A. Permeance B. Eddy current C. Hysteresis D. Reluctance

The magnetic energy stored in an inductor is current. A. Directly proportional to B. Inversely proportional to C. Directly proportional to the square of D. Inversely proportional to the square of

The magnetic flux through a wire loop in a magnetic field does not depend on A. The area of the loop B. The magnitude of the field C. The shape of the loop D. The angle between the plane of the loop and the direction

The magnetic materials should have a large hysteresis loss for one of the following applications. A. Transformers B. AC motors C. Permanent Magnets D. DC generators

The phenomenon by which a magnetic substance becomes a magnet when it is place near a magnet A. Magnetic effect B. Magnetic phenomenon C. Magnetic induction D. Electromagnetic induction

The quantity of magnetism retained by a magnetic material after withdrawal of the magnetizing force is called A. Leftover magnetism B. Hysteresis C. Residual magnetism D. Coercivity

The ratio between the intensity of magnetization produced in a substance to the magnetizing force producing it A. Magnetic Reluctivity B. Magnetic Resistivity C. Magnetic susceptibility D. Magnetic conductivity

The reluctance of a magnetic circuit is not dependent on which of the following? A. Number of turns of coil B. Magnetomotive force C. Flux density in the circuit D. Current in the coil

The reluctance of a magnetic circuit varies with A. length x area B. area -- length C. length + area D. length + area

The straight line passing through the two poles of magnet is called A. Real axis B. Cartesian axis C. Magnetic axis D. Imaginary axis

The temperature coefficient of resistance of eureka is A. positive B. negative C. almost zero D. infinite

The temperature coefficient of resistance of semiconductors is A. positive B. zero C. negative D. infinite

The unit of flux is in cgssystem. A. Tesia B. Gilbert C. Maxwell D. Oersted

Used to maintain strength of magnetic field A. Container B. Air gap C. Keeper D. Source

What is the SI unit of specific resistance or resistivity? A. Ohm-circular mil per inch B. Ohm-circular mil per foot C. Ohm-m D. Ohm-cm

What is the maximum number of electrons that can be accommodated in the last orbit of an atom? A. 4 B. 2 C. 8 D. 18

What is the unit of reluctance? A. Maxwell B. Gauss C. At/Wb D. Weber

What is the value of the absolute permittivity of air? A. 8.854 µF/m B. 8.854 x 10'-12mF/m C. 8.854 x 10A12 F/m D. 8.854 x 10'-12 µF/m

What is used as the dielectric material in high voltage transformers? A. Mica B. Paraffin C. Porcelain D. Oiled paper

What revolves about the positive nucleus in a definite orbit? A. Atom B. Proton C. Electron D. Neutron

What type of bond is formed when there exists some form of collective interactions between the (negatively charged) electrons and (positively charged) nuclei in a solid? A. Ionic B. Covalen t C. Metallic D. Van der Waals

When the relative permeability of a material is slightly more than 1, it is called material. A. diamagnetic B. ferromagnetic C. paramagnetic D. non-magneti

Whenever a conductor cuts magnetic flux, an emf is induced in it. This is known as A. Coulomb's law B. Joule's law C. Faraday's law D. Ohm's law

Whenever a flux inking a coil or current changes, an emf is induced in it. This is known as A. Joule's Law B. Coulomb's Law C. Faraday's first law of electromagnetic induction D. Faraday's second law of electromagnetic induction

Which element has four valence electrons? A. Conductor B. Insulator C. Semiconductor D. Semi- insulator

Which of the following is a diamagnetic material? A. Aluminum B. Silve r C. Air D. Cobalt

Which of the following is a natural magnet? A. Steel B. Magnesia C. Lodestone D. Soft iron

Which of the following is used by temporary magnets as the magnetic material? A. Hardened steel B. Cobalt steel C. Soft iron D. Tungsten steel

Who developed the electromagnetic theory of light in 1862? A. Heinrich Rudolf Hertz B. Wilhelm Rontgen C. James Clerk Maxwell D. Andre Ampere

is an electromagnet with its core in the form of a close magnetic ring. A. Solenoid B. Paraboloid C. Toroid D. Cycloid

. Hysteresis refers to the between flux density of the material and the magnetizing force applied. A. Leading effect B. Ratio C. Equality D.

. Magnetic fields do not interact with A. Moving permanent magnets B. Stationary permanent magnets C. Moving electric charges D. Stationary electric charges

. States that the ratio of the thermal conductivity is proportional to the absolute temperature for all metals. A. Wien's displacement law B. Hartleys law C. Hall's law D. Wiedemann Franz law

. The force of attraction or repulsion between two magnetic poles is inversely proportional to the square of the distance between them. This is known as A. Newton's first law B. Faraday's first law of electromagnetic induction C. Coulomb's first law D. Coulomb's second law

.A theorem which states that an electric current flowing in a circuit produces a magnetic field at external points equivalent to that due to a magnetic shell whose bounding edge is the conductor and whose strength of the current. A. Joule's law B. Faraday's law C. Volta's theorem D. Ampere'stheorem

.The unit of electrical energy is A. Joule B. Watt- second C. Kilowatt- hour D. All of these

.What is the typical saturation flux density for most magnetic materials? A. 4 Wb/mA2 B. 5 Wb/mA2 C. 1 Wb/mA2 D. m

.Which of the following is a paramagnetic material? A. Carbon B. Copper C. Bismut h D. Oxygen

.Which of the following is used by permanent magnets as the magnetic material? A. iron B. nickel C. soft steel D. hardened steel

0ne weber of flux is equal to magnetic lines of force. A. 1 6 B. 1 1 C. x 1 7 D. 10"8

1.Electric field intensity at a point is numerically equal to at that point. A. potential gradient B. potential difference C. dielectric constant D. the force

302. Which of the following is not a basic part of an atom? A. Electron B. Proton C. Neutron D. Coulomb

305. Approximate diameter of an atom A. 10^-10 µµm B. 10^-10 µm C. 10^-10 mm D. 10^-10 m

309. A commonly used model in predicting the atomic structure of a material. A. String model B. Wave model C. Particle model D. Bohr model

310. Is at the center of an atomic structure in a Bohr model. A. electrons B. protons C. neutrons D. nucleus

317. Approximately, how many electrons that could equal to the mass of a single proton or neutron? A. 1,863 electrons B. 1,683 electrons C. 1,638 electrons D. 1,836 electrons

321. Electron is derived from the Greek name elektron which means A. huge B. tiny C. particle D. amber

322. Electric charge of neutron is the same as A. proton B. electron C. current D. atom

325. The atomic weight of an element is determined by the number of A. electrons B. valence electrons C. protons D. protons and neutrons

327. Suppose there is an atom containing eight protons and eight neutrons in the nucleus, and two neutron are added to the nucleus, the resulting atomic weight is about A. 8 B. 10 C. 16 D. 18

328. It is composed of a series of energy levels containing the valence electrons. A. conduction band B. forbidden band C. side band D. valence band

330. _____________ are electrons at the outer shell A. Inside shell electrons B. Conductor electrons C. Outside shell electrons D. Valence electrons

337. An insulating element or material has capability of _________. A. conducting large current B. storing voltage C. storing high current D. preventing short circuit between two conducting wires

338. A law of nature makes certain materials tend to form combinations that will make them stable. How many electrons in the valence orbit are needed to give stability? A. 1 B. 2 C. 4 D. 8

347. In materials, what do you call the region that separates the valence and conduction bands? A. energy gap B. forbidden band C. insulation band D. energy gap or forbidden band

348. What do you call the potential required to remove a valence electron? A. valence potential B. threshold potential C. critical potential D. ionization potential

350. Copper atom has how many protons? A. 1 B. 4 C. 8 D. 29

358. An isotope A. has a negative charge B. has a positive charge C. might have either positive or negative charge D. is neutral

362. A solid, which has no defined crystal structure. A. Crystalline B. Non-crystalline C. Amorphous D. Non-crystalline or Amorphous

363. States that each electron in an atom must have a different set of quantum numbers. A. Quantum principle B. Fermi-Dirac principle C. Spin principle D. Exclusion principle

364. Given an atomic structure of a certain material, what data can you determine out from it? A. atomic number B. atomic mass C. the number of protons and electrons D. all of the above

374. Is a process by which an atom is constantly losing and then regaining electrons? A. oxidation B. passivation C. metallization D. ionization

375. The process in which atoms are changed into ions. A. oxidation B. passivation C. metallization D. ionization

387. One ampere is equal to how many electrons per second? A. 1 x 10^18 electrons/sec. B. 1 x 10^19 electrons/sec. C. 6.25 x 10^18 electrons/sec. D. 6.25 x 10^19 electrons/sec.

392. If a conductor's cross-sectional area is doubled and its length is halved, the value of its resistance will A. double B. quadruple C. decrease by a factor of two D. decrease by a factor of four

396. the reciprocal of resistance A. permeance B. elastance C. inductance D. conductance

397. The science of physical phenomena at very low temperature, approaching absolute zero is called ________. A. cryptanalysis B. cybernetics C. temperature inversion D. cryogenics

399. A wire has a resistance of 5Ω at room temperature and a temperature coefficient α = 4 x 10^-3/°C, calculate the wire resistance at 75°C. A. 8.925 Ω B. 7.925 Ω C. 6.925 Ω D. 6.050 Ω

400. The temperature coefficient of resistance of a certain wire is known to be 0.004/°C at zero degrees Celsius. What would be the temperature coefficient at room temperature? A. 0.00018/°C B. 0.00036/°C C. 0.00180/°C D. 0.00360/°C

404. The ability of a material to resist current flow is called "resistance". What is (are) the factor(s) that affect its value? A. temperature B. length & cross-sectional area C. atomic structure D. all of these

407. One electron volt (eV) is equivalent to A. 1.0 watt-sec B. 1.6 x 10^-19 watt-sec C. 1.0 Joule D. 1.6 x 10^-19 Joules

408. What law that describes the force of attraction or repulsion between two charges is directly proportional to their strengths and inversely proportional to the square of the distance between them? A. Coulomb's first law B. Coulomb's second law C. Coulomb's third law D. Coulomb's law or law of electrostatics

409. What is the law whereby the force of attraction and repulsion between poles is inversely proportional to the square of the distance between them? A. Newton's first law B. Newton's second law C. Norton's law D. Coulomb's second law

410. Is usually used to detect the presence of electric charge. A. experimental charge B. unit charge C. dipole D. test charge

412. Three charges of +5 C, -6 C and +7 C are placed inside a sphere, what is the total charge of the sphere? A. +5 Coulomb B. -6 Coulomb C. -7 Coulomb D. +6 Coulomb

413. A combination of two charges, with equal charge magnitude but opposite signs. A. magnetic dipole B. static dipole C. dynamic dipole D. electric dipole

415. Refers to a force of field that exists between ions where they either repel or attract each other. A. Resisting field B. Potential field C. Dielectric D. Electromotive

416. The imaginary lines representing the electric field. A. Electric field B. Electric flux C. Electric flux density D. Electric lines of force

417. What is true in visualizing electric field lines of force from a charge body? A. Field lines are continuous curve and they never intersect. B. The spacing between these lines increases as they get far from the charged body. C. The number of field lines is directly proportional to the magnitude of the electric field. D. All of the above.

420. Electric lines of force leave and enter the charge surface at what angle? A. 15° B. 30° C. 45° D. 90°

427. An electric charge produces a total electric field of 6 Coulombs, calculate the electric flux density in an area of one square meter (1m2). A. 1 C/m^2 B. 2 C/m^2 C. 4 C/m^2 D. 6 C/m^2

428. The measure of density of the electric charge A. Electric gradient B. Electric current C. Electric charge D. Electric potential

433. What is the term used to express the amount of electrical energy stored in an electrostatic field? A. Volts B. Watts C. Coulombs D. Joules

438. The basic law for interaction of charged bodies at rest. A. Charged law B. Gauss' law C. Faraday's law D. Coulomb's law

441. In 1784, who demonstrated that the force between charges is inversely related to the square of the distance between them? A. Maxwell B. Gauss C. Tesla D. Coulomb

443. What will happen when two opposite charges get closer? A. repels less B. attracts less C. repels more D. attracts more

445. The measure of electric field strength per unit length is known as electric field intensity or simply electric intensity. What is its unit? A. Volt/meter (V/m) B. Joules/Coulomb-meter (J/Cm) C. Newton/Coulomb (N/C) D. All of the above

449. A 2nC point charge will produce what potential at 2 m away? A. 4.0 Volts B. 6.0 Volts C. 7.5 Volts D. 9.0 Volts

456. In a magnet, what do you call the point in which the magnetic lines of force is maximum? A. maximum pole B. intensified pole C. unit pole D. magnetic pole

460. In a magnet, the straight line passing through the two poles is called A. real axis B. imaginary axis C. Cartesian axis D. magnetic axis

463. What do you call the quantity of magnetism retained by a magnetic material after the withdrawal of a magnetizing force? A. Left over magnetism B. Coercivity C. Hysteresis D. Residual magnetism

477. Permeability of a material means: A. The ability of the material to conduct electric field B. The conductivity of the material for electromagnetic field C. The ability of the material to hold magnetic flux D. The conductivity of the material for magnetic lines of force

479. Cores of magnetic equipment use magnetic material which has A. very low permeability B. moderate permeability C. low permeability D. high permeability

483. The imaginary lines representing the magnetic field. A. magnetic field B. magnetic flux C. magnetic flux density D. magnetic lines of force

490. The unit of magnetic flux density in SI: A. Gauss B. Weber C. Maxwell D. Tesla

497. If the distance between two magnetic poles is halve, the force between them A. decreases two times B. decreases four times C. increases two times D. increases four times

502. The Gauss is a unit of A. permeability B. electromagnetic force C. magnetic force D. magnetic flux density

506. A magnetic flux of 500,000,000 lines is equivalent to A. 5 x 10^8 Maxwells B. 5 Weber C. 500 x 10^6 MAxwells D. all of these

510. Electrical current is analogous to _________ in magnetic circuits. A. Ampere-turn B. Magnetomotive force C. Magnetizing force D. Flux

512. Resistance in electrical circuits is analogous to _________ in magnetic circuits. A. Conductance B. Permeance C. Elastance D. reluctance

513. The property of a material which opposes the creation of magnetic flux. A. elastance B. permeance C. susceptance D. reluctance

518. It is easier to establish flux line in soft iron than it is to establish them in air, this is because iron has a lower A. Permeance B. Inductance C. elastance D. reluctance

523. Magnetomotive force has a unit of A. Volt (V) B. Watt (W) C. Joule (J) D. Ampere-turn (At)

531. In a magnetic circuit, a flux that drifts away from its intended path is called A. lost flux B. linked flux C. drift flux D. leakage flux

532. Is the quantity of magnetizing force needed to counter balance the residual magnetism of a magnetic material. A. hysteresis B. degaussing C. retentivity D. coercivity

533. What do you call the loss of electrical energy in counter balancing the residual magnetism in each cycle? A. hysteresis B. magnetomotive C. leakage D. coercivity

536. An advantage of an electromagnet over a permanent magnet A. An electromagnet can be demagnetized B. An electromagnet is simpler C. An electromagnet is cheaper D. An electromagnet can be switched ON and OFF

545. Is used to maintain strength of magnetic field. A. storer B. energizer C. gausser D. keeper

A factor used to correct for the electrostatic forces of the more distant ions in an ionic solid. A. Avogadro's number B. Planck's constant C. Boltzmann's constant D. Madelung constant

A law relating between the magnetic and electric susceptibilities and the absolute temperatures which is followed b ferromagnets, antiferromagnets, non-polar ferroelectrics, antiferroelectrics and some paramagnets. A. Curie's Law B. Child's Law C. CR Law D. Curie-Weiss Law

A law that states that the polarity of the induced voltage will oppose the change in magnetic flux causing the induction. A. Joule's law B. Faraday's law C. Coulomb's law D. Lenz' law

A permanent magnet does not exert a force on A. an unmagnetized iron bar B. a magnetized iron bar C. a moving electric charge D. a stationary electric charge

A t/m is a unit of A. Mmf B. Emf C. Reluctance D. Magnetizing force

All matters (gas, liquid and solid) are composed of A. Neutrons B. Particles C. Electron s D. Atoms

Back emf refers to the A. Current equal to the applied emf B. Opposing emf C. Current opposing the applied emf D. Voltage opposing the applied emf

Bonding of atoms that is due to the force of attraction between positive ions and a group of negative ions A. Ionic bond B. Covalent Bond C. Electrostatic Bond D. Metallic bond

Defined as the flux density produced in it due to its own induced magnetism A. Magnetic field intensity B. Electric field intensity C. Electromagnetic field intensity D. Intensity magnetization

Electrons at the outer shell are called A. Outer shell electrons B. Inner shell electrons C. Semiconductor electrons D. Valence electrons

Flux linkages equals A. Flux times area of core B. Flux times number of turns times area of core C. Flux times number of turns times length of core D. Flux times number of turns

Formed when there exist distant electronic interactions between (opposite) charges present in the neighboring atoms or molecules. A. Ionic bond B. Covalent bond C. Metallic bond D. Van der Waals bond

Gases whose particles are charged are known as A. Conductors B. Insulators C. Gaseous Conductors D. Plasma

If a 20 V potential is applied across a relay coil with 50 turns having 1 Q of resistance, the total magnetomotive producing magnetic flux in the circuit is A. 10 Wb B. 50 T C. 1000 A t/m D. 1000 A.t

If on looking at any one end of a solenoid; the direction of current flow is found to be clockwise then the end under observation is a south pole. This is known as A. Right hand rule B. Left hand rule C. Cork screw rule D. End Rule

If you hold the conductor with right hand so that the stretched thumb points in the direction of the current, then encircling fingers will give the direction of magnetic lines of force round the conductor. This is known as A. Left hand cork screw rule B. Right hand cork screw rule C. Left hand rule D. Right hand rule

Lenz' law states that the direction of the induced emf and hence current A. Is determined by the rate of current flux B. Is found by the right hand rule C. Is found by the left hand rule D. Always opposes the cause producing it

Magnetic intensity is a A. Phasor quantity B. Physical quantity C. Scalar quantity D. Vector quantity

Ohm's law can be used only to a circuit or component. A. Unilateral B. Exponential C. Trivalen t D. Linear

One electron volt (1 eV) is equivalent to joules A. 1.3 x 10'-19 B. 1.4 x 10'-19 C. 1.5 x 10'-19 D. 1.6 x 10'-19

The B-H curve of is not a straight line. A. air B. wood C. silicon steel D. soft iron

The ability of a material to conduct magnetic flux through it. A. Permittivity B. Reluctivity C. Conductivity D. Permeability

The core of a magnetic equipment uses a magnetic material with A. Least permeability B. Low permeability C. Moderate permeability D. High permeability

The core of a transformer heats up when its primary is fed from an ac source because of A. permeability B. ferromagnetism C. reluctance of core D. hysteresis loss

The emf induced in a coil due to the change of its own flux linked with it is called A. Mutually induced emf B. Dynamically induced emf C. Statically induced emf D. Self induced emf

The flux density in an air-cored coil is 10 - Wb/m 2. With a cast iron core of relative permeability 100 inserted, the flux density will become A. 10 - Wb/m 2 B. 10 -2 Wb/m 2 C. 10 Wb/m 2 D. 0.1 Wb/m"2

The force between two magnetic poles varies with the distance between them. The variation is to the square of that distance. A. Equal B. Greater than C. Directly proportional D. Inversely proportional

The force which set ups or tends to set up magnetic flux in a magnetic circuit A. Dynamic force B. Electromotive force C. Potential difference D. Magnetomotive force

The magnetic field of a bar magnet most closely resembles the magnetic field of A. a horseshoe magnet B. a straight current- carrying wire C. a stream of electrons moving parallel to one another D. a current- carrying wire loop

The permittivity of a material is given by one of the following formulas. A. DE B. E/D C. D 2/E D. D/E

The ratio of the total flux (flux in iron path) to the useful flux (flux in air gap) A. Leakage flux B. Leakage current C. Leakage coefficient D. Leakage factor

The relation between absolute permittivity of air (E0), absolute permeability of air (µ0) and velocity of light (c) is given by A. µ0E0 = cA2 B. µ0E0 = c C. 1/µ0E0 =c D. 1/ c"

The science of adapting electronics to aerospace flight. A. Avionics B. Aerotronics C. Aerodynamic s D. Astrionics

The uncharged particles which have no effect on its atomic charge. A. Nucleons B. Electrons C. Protons D. Neutrons

There are how many compounds available in nature? A. 105 B. 1000 C. 300,000 D. Unlimited

What determines the value of the temperature coefficient of resistance of a material? A. length B. cross-sectional area C. volume D. nature and temperature

What is another name for relative permittivity? A. Dielectric strength B. Electric intensity C. Potential gradient D. Dielectric constant

What is the SI unit of conductivity? A. Ohms/m B. Ohms-m C. Siemens-m D. Siemens/m

What is the SI unit of reluctance? A. At B. At/m C. N/Wb D. At/Wb

What is the usual value of leakage coefficient for electrical machines? A. 0.5 to 1 B. 1 to 5 C. 5 to 10 D. 1.15 to 1.25

When a current carrying conductor is placed in a magnetic field, the maximum force will act on the conductor when the conductor is at an angle of to the magnetic field. A. 45o B. 60o C. 30o D. 90o

When the current flows, the magnetic field ...conductor is in what direction? A. The same as the current direction B. Opposite the current direction C. Omnidirectional D. In the direction determined by the left hand rule

Which of the following has the highest permeability? A. Soft iron B. Steel C. Air D. Permalloy

Which of the following is a paramagnetic material? A. Carbon B. Bismuth C. Copper D. Oxygen

Which of the following materials has permeability slightly less than that of free space? A. Paramagnetic B. Non- magnetic C. Ferromagneti c D. Diamagnetic

Who demonstrated that there are magnetic effects around every current-carrying conductor and that current-carrying conductors can attract and repel each other just likemagnets? A. Luigi Galvani B. Hans Christian Oersted C. Charles Coulomb D. Andre Ampere

Why is it that the magnitude of magnetomotive force required for air gap is much greater than that required for iron part of a magnetic circuit? A. Because air is a gas B. Because air has the highest relative permeability C. Because air is a conductor of magnetic flux D. Because air has the lowest relative permeability

01. [ELEX]

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