1. CURRENT ELECTRICITY AND ETC
33. International ohm is defined in terms of resistance of A. a column of mercury B. a cube of carbon C. unit length of metal wire D. a cube of copper
A
33. The area of hysteresis loop represents hysteresis loss in A. J/m3/s B. J/cycle C. J/s D. J/m3
A
37. Charging a lead-acid cell causes the electrolyte to become A. stronger B. stable C. weaker D. water
A
1. A natural magnet is called A. steel B. lodestone C. magnetism D. soft iron
B
10. In the left hand rule, thumb always represents A. voltage ` B. current C. direction of force on conductor D. magnetic field
C
10. Permeance is analogous to A. conductance B. resistance C. reluctance D. none of these
A
1.What are the minimum requirements to cause the flow of current? A. A voltage source, an ammeter, a conductor and an insulator B. A voltage source, a switch and a resistor C. A voltage source and a conductor D. A voltage source, a conductor and an insulator
C
16. Leakage factor is A. less than unity B. equal to unity C. more than unity D. zero
C
11. The permeability of a material means A. strength of permanent magnet B. strength of an electromagnet C. the magnetization left in the iron after exciting field has been removed D. the conductivity of a material for magnetic lines of force
D
20. Interaction between the neighboring dipoles is negligible in case of a A. paramagnetic material B. diamagnetic material C. antiferromagnetic material D. ferrimagnetic material
A
20. Which of the following acts as depolarizer in dry cell? A. manganese dioxide B. zinc chloride C. ammonium chloride D. carbon powder
A
21. One advantage of a secondary cell is that it A. can be recharged B. can be used for portable equipment C. it is compact, easy to carry D. cannot be recharged
A
21. When steel toroidal ring is magnetized by passing current through its coil, it develops no magnetic poles A. True B. False C. Partly true D. Partly false
A
22. If a dielectric is placed in a electric field, the field strength A. decreases B. increases C. remains the same D. becomes zero
A
22. The relative permeability µ for iron is A. 5000 B. 7000 C. 3000 D. 1000
A
23. In a series circuit the current is A. constant B. always zero C. proportional to the resistance D. different in different resistors
A
24. A capacitance C is charged through a resistance R. The time constant of the charging circuit is given by A. RC B. 1/RC C. C/R D. R/C
A
24. Secondary cell can produce large amounts of power for a A. short time and can be recharged B.long time and can be recharged C.short time and cannot be recharged D.long time and cannot be recharged
A
25. Ferrimagnetic materials generally behave as a A. semiconductor B. conductor C. insulator D. any of A, B, or C
A
25. Gassing occurs in the process of A. charging an accumulator B. charging a dry cell C. discharging an accumulator D. discharging a dry cell
A
25. The resistance R 1 and R2 are connected in parallel. The ratio of values of resistance R 1 : R 2 is 4 : 1. The currents in R 1 : R2 will be equal to A. 1 : 4 B. 1 : 1 C. 4 : 1 D. 4 : 4
A
26. Mutual inductance can also be defined as: A. M = N2 dφ/di B. L1/L2 C. sqrt(L1/L2) D. M = sqrt(L1*L2)
A
26. Transformer cores operating at microwave frequency ranges are generally made up of A. ferrites B. silicon steel C. supermalloy D. alnico V
A
27. Internal heating of a capacitor is usually attributed to A. leakage resistance B. electron movement C. plate vibration D. dielectric charge
A
27. The lead acid accumulator should be recharged when the specific gravity of the electrolyte is about A. 1.15 B. 1.80 C. 1.25 D. 1.35
A
27. The magnetic materials which can be easily magnetized in both directions are known as A. soft magnetic materials B. hard magnetic materials C. low hysteresis loss materials D. high hysteresis loss materials
A
29. Three elements having conductance G1, G2 and G3 are connected in parallel. Their combined conductance will be A. G1 + G2 + G3 B. 1/G1 + G2 + G3 C. G1G2 + G2 G3 + G3G1/ (G1 + G2 + G3) D. 1/ (1/G1 + 1/ G2 + 1/G3)
A
3. In the electric field, the potential is the work done in joules A. to bring positive charge of one coulomb from infinity to that point B. to bring any charge from infinity to that point C. in moving a unit positive charge from one point to the other point D. to bring any charge from any point to infinity
A
30. The coupling coefficient denotes A. the degree of magnetic linkage B. whether the reluctance remains constant C. the variation of inductance between the two coils D. whether the flux linkage is constant
A
31. It is difficult to magnetize steel because of its A. low permeability B. high retentivity C. high permeability D. high density
A
32. In electrical machines, laminated cores are used with a view of reducing A. eddy current loss B. copper loss C. hysteresis loss D. windage loss
A
36. Hysteresis losses can be reduced by A. using grain-oriented silicon steel B. increasing the frequency of the field C. laminating the core D. none of these
A
36. Which of the following is a primary cell A. mercury oxide B. lead-acid C. nickel-iron-alkaline D. nickel-cadmium-alkaline
A
4. A collapsing field around a coil A. tends to oppose the decay of coil current B. helps the decay of coil current C. tends to aid current flow reversal D. does not affect the coil current flow
A
4.Resistance of a conductor increases when A. its length increases B. its area increases C. both length and area increases D. specific resistance is kept constant
A
6. Distilled or approved water is used in electrolytes because it A. prevents or slows down local action B. speeds up electrochemical action C. improves specific gravity D. prevents polarization
A
6.The specific resistance ρ is defined as A. resistance of a conductor which has a length of 1 m and cross-section of 1 m^2 at 20 deg C B.resistance of any conductor at 25degC C. resistance of any conductor at 20degC D. resistance of a conductor which has a length of 1 m and cross-section of 1 cm^2 at 20deg C
A
7.The field F = yi + x j is a A. rotational field B. irrotational field C. conservative field D. static electric field
A
8.It was experimentally found by James Prescott Joule that the heat produced in a current carrying conductor is proportional to A. the square of the current B. square of resistance C. the current D. inversely proportional to time
A
9.What will happen to an insulating medium if voltage more than the breakdown voltage is applied? A. it will get punctured B. it will become magnetic C. it will melt D. its molecular structure will change
A
1. Absolute permittivity of vacuum is taken as A. 8.854 x 10 -6 farad/meter B. 8.854 x 10 -12 farad/meter C. 8.854 x 10 -9 farad/meter D. 8.854 x 1012 farad/meter
B
1.The coefficient of self-inductance of a coil is defined as A. NI/ φ B. Nφ/I C.φ / NI D.φI / N
B
10. The action of a dry cell is to change A. chemical action to mechanical energy B. chemical action to electrical energy C. electrical energy into mechanical energy D. electrical energy into magnetic energy
B
10. Which medium has the highest value of dielectric strength? A. glass B. mica C. porcelain D. quartz
B
11. Polarization in dry cell can be got rid of by A. coating the electrodes of the cell B. chemical means C. discharging the cell D. disposing the cell
B
11. The maximum value of potential gradient in a cable occurs in A. outer sheath B. insulation B. conductor D. uniformly all over
B
12. The two main defects of the primary cell are A. polarization and sulphation B. local action and polarization C. buckling and polarization D. sulphation and buckling
B
12. When the magnetic flux (φ) and the area (A) under its influence are known, the magnetic flux density (B) can be given as A. B = φ A B. B = φ/A C. B = A /φ D. B = φ A^2
B
13. Inside a hollow spherical conductor A. electric field is constant B. electric field is zero C. electric field changes with distance from the center of the sphere D. electric field is unity
B
13. The average dry cell gives an approximate voltage of A. 1.3 V B. 1.5 V C. 1.1 V D. 1.7 V
B
14. Capacitors are said to A. block a.c. and pass d.c. B. block d.c. and pass a.c. C. pass a.c. and d.c. D. block a.c. and d.c.
B
14. Relative permeability of a material is given by (K is susceptibility of the material) A. 1 + µ0K B. 1+ K/µ0 C. 1 + µ0 /K D. µ0H
B
14. The curve representing Ohm's law is A. a parabola B. linear C. sine function D. a hyperbola
B
14. The effect of the inductance of a coil on a constant direct current is that A.it strengthens the current B. it does not affect the constant direct current C. it decreases the current D. it causes a higher voltage drop
B
16. The value of permeability for the free space is A. 4 x 10^ -7 Hm -1 B. 4π x 10 -7 Hm -1 C. 4π x 10^7 Hm -1 D. 1/4π× 10 − 7 Hm−1
B
18. According to Lenz's law the direction of induced e.m.f. and hence current A. may be found by the right hand rule B. always opposes the cause producing it C. is determined by the rate of cutting flux D. may be found by the left hand rule
B
18. Cells are connected in series to A. decrease the voltage output B. increase the voltage output C. decrease the internal resistance D. increase the current capacity
B
18. The sum of the magnetic moments in unit volume of the solid is called A. field strength B. magnetization C. permeability D. susceptibility
B
19. Sparking occurs when a load is switched off because the circuit has high A. capacitance B. inductance C. resistance D. impedance
B
19. The presence of an electric current is made known by A. flashing B. effects produced C. cracking D. electric shock
B
20. An electric current can neither be nor . A. felt, seen B. seen, touched C. seen, produced any effect D. produced, felt
B
20. The flux linked with a coil of inductance L carrying current i is d(Li)/dt A. True B. False C. Partly true D. Partly false
B
21. One farad is A. coulomb-joule B. one coulomb per volt C. joule per volt D. one volt per coulomb
B
23. If the medium of a parallel-plate capacitor consists of mica and air, the capacitance is increased by A. increasing the air space B. increasing the area of the plates C. decreasing the area of the plates D. increasing the thickness of mica
B
24. Which of the following has the highest value of relative permeability µr? A. iron B. supermalloy C. Mu-metal D. 4% Si - Fe
B
26. In a capacitor, the electric charge is stored in A. metal plates B. dielectric C. dielectric as well as metal plates D. neither dielectric nor metal plates
B
27. The voltage applied across an electric press was reduced by 50%. The power consumed by the press will be reduced by A. 25% B. 75% C. 60% D. 50%
B
28. Eddy current loss can be minimized by A. decreasing the resistance of magnetic medium B. increasing the resistance of magnetic medium C. decreasing the permeability of magnetic medium D. none of the above
B
29. Electrolyte of a storage battery is formed by adding A. water to hydrochloric acid B. sulphuric acid to water C. hydrochloric acid to water D. water to sulphuric acid
B
3. Externally, magnetic line of force travels A. south to north B. north to south C. negative to positive D. in both directions
B
30. Four resistances R 1, R 2, R 3 and R 4 are connected in series against 220 V supply. The resistances are such that R 1 > R 2 > R 3 > R 4 . The least power consumption will be in A. resistor R1 B. resistor R4 C. resistor R3 D. resistor R 2
B
30. When the electrolyte of a storage battery is low it is usually proper to A.add a special weak acid solution B. top up with distilled water C. charge the battery for a short time before adding an electrolyte D. drain the battery completely and fill it with fresh electrolyte
B
31. The ampere hour capacity of battery depends on A. the thickness of the plates B. the area of the plates C. the strength of the electrolytes D. the distance between the plates
B
34. According to Hysteresis law, hysteresis loss in a material is proportional to A. B^1.2 B. B^1.6 C. B^0.6 D. B^3.6
B
34. It is not desirable to leave a lead storage battery in a discharged state for a long time mainly because A. electrolyte will attack the container B. plates will become sulphated C. electrolyte will become weak D. acid will evaporate
B
4. In electroplating, the positive electrode is called the A. cathode B. anode C. terminal D. iontrap
B
43. The advantage of the iron-nickel battery over the lead-acid battery is that A.it has a much higher efficiency B. it needs less maintenance C. the cell voltage of the iron-nickel battery is higher D. it is much cheaper
B
5. Coulomb's law for the force between electric charges most closely resembles with A. Gauss theorem B. Newton's law of gravitation C. Law of conservation of energy D. Newton's laws of motion
B
7. A conductor of length L has current I passing through it, when it is placed parallel to a strong magnetic field. The force experienced by the conductor will be A. BLI B. zero C. B^2LI D. BL^2I
B
7. The condition of a liquid electrolyte is measured in terms of its A. current value B. specific gravity C. acid content D. voltage output
B
7.The resistance of a conductor, when its temperature is increased A. remains constant B. increases C. varies D. decreases
B
9. Local action in the primary cell can be rectified by A. charging the cell B. amalgamating the zinc electrode with mercury C. using the cell for just few minutes D. dry cell
B
9. The magnetic potential in a magnetic circuit can be measured in terms of A. farads B. M.M.F. C. coulombs D. none of these
B
ELECTROLYSIS AND STORAGE BATTERIES 1. Electrochemical equivalent is A.ratio of atomic weight of an element to atomic weight of hydrogen B. mass of the element liberated per unit quantity of hydrogen C. ratio of atomic weight of valency D. none of the above
B
11. The coefficient of coupling between two air core coils depends on A.self inductance of the two coils only B.mutual inductance between the two coils only C. mutual inductance and self inductance of the two coils D. none of the above
C
11. When current flows in a conductor, heat is produced because A. heat α I^2 B. of electronic collision C. of interatomic collision D. of Joule's law
C
15. Good smoothing factor of a coil depends on the A. terminal voltage B. property of the wire of the coil C. inductance of the coil D. cross-sectional area of the wire of the coil
C
15. The condition in Ohm's law is that A. ratio V/I should be constant B. current should be proportional to voltage C. the temperature should remain constant D. the temperature should vary
C
15. The relative permeability of paramagnetic substance is A. slightly less than 1 B. equal to 1 C. slightly greater than 1 D. very much greater than 1
C
15. When n cells, each of emf E volts, and internal resistance r ohms are connected in series, the current i through an external resistance R ohms is given by A. i = E/ (R + r/n) B. i = E/ (R + n) C. i = nE/ (R+nr) D. i = E / (r +nR)
C
16. Ohm's law does not apply to A.conductors B.conductors when there is change in temperature C. semiconductor D. a.c. circuit
C
16. The effect of the dielectric is to A. increase the capacitance B. decrease the capacitance C. reduce the working voltage D. increase the distance between the plates
C
17. Cells are connected in parallel to A. increase the internal resistance B. decrease the current capacity C. increase the current capacity D. increase the voltage output
C
18. Ohm's law can be applied with certain reservations to A rectifying devices B. semiconductors C. electrolytes D. thermionic valves
C
19. Which of the following materials does not have permanent magnetic dipole A. paramagnetic B. antiferromagnetic C. diamagnetic D. ferrimagnetic
C
2. Relative permittivity of vacuum is A. zero B. 8.854 x 10 -6 farad/meter C. unity D. 9 x 109 farad/meter
C
2.Which of the following statement is incorrect? A.Whenever the flux linking with the coil or circuit changes the emf is produced. B.The direction of dynamically induced emf can be determined by Flemming's right hand rule. C. Coefficient of coupling for tightly coupled coil is zero. D. The coefficient of self-inductance is proportional to the square of number of turns on it.
C
20. The power dissipated in a pure capacitor is A. maximum B. minimum C. zero D. depends on the size and voltage
C
21. The presence of the current is only made known by the effect it produces. Three important effects are A.heating, electric shock and generation B.generation, chemical and electric shock C.heating, magnetic and electric shock D. heating, magnetic and chemical
C
22. The composition of a secondary cell is A. zinc, copper and dilute sulphuric acid B. zinc, carbon and dilute sulphuric acid C. lead, lead peroxide and dilute sulphuric acid D. zinc, copper and dilute boric acid
C
23. Nickel-cadmium dry cell is becoming popular in power supplies to electronic calculators because A. it has a standard shape B. it is dry C. it is rechargeable D. it is easily manufactured
C
23. The growth of current in an inductive circuit follows A. hyperbolic law B. Ohm's law C. exponential law D. linear law
C
25. A circuit component that opposes the change in the circuit voltage is A. resistance B. inductance C. capacitance D. none of these
C
25. The time constant is the time it takes the current in an inductive circuit to rise to A. 66% of its final steady state value B. 70% of its final steady state value C. 63% of its final steady state value D. 50% of its final steady state value
C
12. Heating effect of current has undesirable side effect in A. electric oven B. electric iron C. immersion heater D. vacuum cleaner
D
12. While comparing magnetic and electric circuits, the flux of magnetic circuit is compared with which parameter of electric circuit? A. e.m.f. B. current density C. conductivity D. current
D
14. To obtain a high voltage of about 1.9 V from a dry cell, one would use A. Western standard cell B. Leclanche cell C. Nickel cadmium cell D. Magnesium cell
D
15. Which statement influences the capacity of a capacitor? A.area of the plates, thickness of the plates and the rate of charge B.area of the plates, dielectric and the rate of charge C. distance between the plates, dielectric and thickness of the plates D. distance between the plates, area of the plates and dielectric
D
17. Electrolytic capacitor is the most commonly used type but it has two disadvantages, namely A.low insulation resistance and suitable for d.c. only B.high insulation resistance and suitable for a.c. only C.high capacitance and high insulation resistance D. high capacitance and low insulation resistance
D
17. Ohm's law is applicable to A. electric arc B. rectifying devices C. gas discharge lamps D. none of these
D
17. The magnetization in any magnetic material appears as a result of A. electrons orbital motion B. electron spin C. spin of the nucleus about its axis D. all of these
D
19. A sphere of one meter radius can attain a maximum potential of A. 1000 V B. 3 million volts C. 30 kV D. 3 kV
D
2. A magnet is able to attract A. iron, aluminum and brass B. iron, cobalt and zinc C. iron, copper and nickel D. nickel, cobalt and steel
D
2. The mass of material deposited over an electrode is A. proportional to voltage B. proportional to time only C. proportional to current only D. proportional to quantity of electricity and electrochemical equivalent
D
21. Each ferromagnetic material has characteristic temperature above which its properties are quite different from those below that temperature. This temperature is called A. transition temperature B. Faraday's temperature C. demagnetization temperature D. Curie temperature
D
22. Air gap in the iron core of an inductor prevents A. hysteresis loss B. flux change C. transformer action D. core saturation
D
22. Voltage applied across a circuit, acts as A. mass of electrons B. negative ions C. a component of current D. a force
D
23. Which of the following material is used for making permanent magnets A. carbon steel B. platinum cobalt C. Alnico V D. All of these
D
24. In a parallel circuit the potential difference across the resistance A. varies B. is different from the applied voltage C. is sometimes constant D. is always constant
D
24. The time constant of an inductive circuit is defined as the ratio of A. R/L B. Rt/L C. Lt/R D. L/R
D
26. A resistance of 4 ohms is connected across 100 V supply. When another resistor 'R' ohms is connected in parallel with 4 ohms, the total current taken from supply was found to be 50 A. The value of resistance 'R' is A. 2 ohms B. 3 ohms C. 5 ohms D. 4 ohms
D
26. The condition of a secondary cell can be determined by A. its terminal voltage B. the color of the electrolyte C. the level of the electrolyte D. the terminal voltage and strength of the electrolyte
D
27. The mutual inductance of two coils is maximum when the coils are A. inclined at an angle of 45 degrees B. at right angle to each other C. facing each other D. touching each other
D
28. Other types of accumulators besides the lead acid type are A. alkaline batteries only B. alkaline and solar batteries C. alkaline and dry batteries D. nickel-cadmium batteries
D
28. The ohmmeter reading for a shorted capacitor is A. infinity B. few kilo ohms C. few mega ohms D. zero
D
28. The value of mutual inductance in terms of self inductance of the two coils L 1 and L2 is proportional to A. L1L 2 B. L1/L 2 C. sqrt(L1/ L2) D. sqrt(L1L2)
D
3. The mass of an ion liberated at an electrode is directly proportional to the quantity of electricity which passes through the electrolyte. The above statement is associated with A. Gauss's theorem B. Laplace law C. Weber and Ewing's theory D. laws of electrolysis
D
3.Which of the following statements about inductance of a coil is true? A.Inductance is a characteristic of coil occurring only in case of A.C. B.Inductance appears only if the coil has an iron core. C.Inductance is only another expression for self-induced voltage. D. Inductance characterizes the magnetic properties of a coil which are significant for the value of self-induced voltage generated due to current change in the coil.
D
3.Which of the following statements is correct? A.The resistance does not play an important role in electrical engineering. B.The resistance of a wire does not depend upon its material. C.The resistance of most of the materials is independent of the temperature. D. The resistance of conductor is the hindrance by which the conductor opposes the flow of the current.
D
31. When current flows through heater coil it glows but supply wiring does not glow because A.supply wiring is covered with insulation layer B.current through supply line flows at slower speed C.supply wires are made of superior material D.resistance of heater coil is more than that of supply wires
D
32. To keep the terminals of a lead acid storage battery free from corrosion, it is advisable to A. clean the terminals frequently B. charge for battery at frequent intervals C. keep the electrolyte level low D. apply petroleum jelly
D
35. A partially discharged lead storage battery may be brought back to full charge by A. adding sulphuric acid B. adding distilled water C. applying ac voltage across the terminals D. applying dc voltage across the terminals
D
35. The current carrying capacity of the fuse material depends on A. length B. material C. cross-sectional area D. all of these
D
39. Which of the following affects the capacity of a lead-acid battery? A. temperature B. discharge time C. specific gravity D. all of these
D
4. A material commonly used for shielding or screening magnetism is A. brass B. aluminum C. copper D. soft iron
D
40. During the charging period of a lead-acid battery, the charging rate is lowered to prevent violent gassing because A.the gasses given off are explosive B.evaporation of the electrolyte will weaken its effect C.the cells will be subjected to excessive pressure D. violent gassing tends to wash the active material from the plates
D
5.Energy stored in an inductance is given by A. 2LI2 joules B. 0 joule C. Nφ/I joules D. 1/2 LI^2 joules
D
6.Which of the following equations is correct? A.∫Ed l = 0 B. E ds = q C.∫ E d s = q/ε D. ∫Edl = 0, s →s
D
8. The force between two magnetic poles varies with distance between them. The variation is A. in direct proportion to the distance B. in inverse proportion to the distance C. in direct proportion to the square of the distance D. in inverse proportion to the square of the distance
D
8.Dielectric strength of a material depends on A. moisture content B. thickness C. temperature D. all of these
D
9.The left hand rule correlates A.self induction, mutual induction and direction of force on a conductor B.magnetic field, electric field and direction of force on a conductor C.current, induced emf and direction of force on a conductor D. current, magnetic field and direction of force on a conductor
D
13. While comparing magnetic and electric circuits, the point of dissimilarity exists while considering A. flux and current flow B. permeance and conductance C. m.m.f. and e.m.f. D. reluctance and resistance
A
16. When n cells, each of emf E volts, and internal resistance r ohms are connected in parallel, the strength of the current i is given by A. E/ (R + r/n) B. nE/ (r + nR) C. E/ (n + Rr) D. E / (r + n/R)
A
17. The law that induces emf and current always opposes the cause producing them was discovered by A. Lenz B. Faraday C. Maxwell D. Ohm
A
18. In a radio, a gang condenser is a type of A. air capacitor B. paper capacitor C. ceramic capacitor D. electrolytic capacitor
A
19. The function of the depolarizer in carbon zinc cell is that A. it converts the produced hydrogen into water B. it prevents the fast chemical action on the zinc container C. it synthesizes the decomposed electrolyte D. it absorbs the oxygen produced in the cell
A
2.Out of the following, select the best conductor of electricity. A. Graphite B. China clay C. Porcelain D. None of these
A
10. Temperature coefficient of a conductor is defined as the A. increase in resistance per ohm per degree centigrade B. increase in resistance per degree centigrade C. increase in resistance per degree absolute D. decrease in resistance per ohm per degree centigrade
A
12. A region around a stationary electric charge has A. electric field B. magnetic field C. both electric and magnetic field D. neither of the two
A
13. The relative permeability µr is given by A. B/ µoH B. µ0/µ C. B/H D. µ0/H
A
13. The resistance of carbon (filament in carbon-filament lamps) when its temperature is decreased A. increases B. decreases C. remains the same D. increases enormously
A
28. Two electric presses are connected in parallel. The resistance of the first press is 100 ohms and that of the second is 300 ohms. The total current taken by both the presses is 4 A. The ratio of current taken by first : second will be equal to A. 2 : 3 B. 1 : 3 C. 3 : 1 D. 1.2 : 3
C
29. Coupling coefficient k, a term much used in radio work can be obtained from A. K = Msqrt(L1/ L2) B. K = M sqrt(L1/L2) C. K= M / sqrt( L1L2) D. K = ML1L 2
C
32. Resistors commonly used in power circuits are A. carbon resistors B. etched circuit resistors C. wire wound resistors D. deposited metal resistors
C
33. The internal resistance of a discharged battery compared with a charged one A. is more B. is less C. remains the same D. is negative
C
34. Which of the following has negative coefficient of resistance? A.wire wound resistor B. non-metals C.thermistor D. metals
C
35. A degaussing is the process of A.removing gases from materials B.removal of magnetic impurities C. demagnetizing metallic part D.magnetizing nonmetallic part
C
38. Separators in storage battery cell are designed to prevent the plates from A. touching the electrolyte B. touching the container C. shorting together D. shorting to the sediment
C
4. The unit of field intensity is A. coulomb B. coulomb/m^2 C. newtons/coulomb D. newtons/m^2
C
41. A fuel cell converts________energy into electrical energy. A. mechanical B. magnetic C. chemical D. solar
C
42. A cell which is used as voltage reference source for instrument calibration is A. solar cell B. dry cell C. mercury-cadmium cell D. nickel-cadmium cell
C
44. While charging accumulators, one should A.check the acid level with a lighted match B.short the cells to see if they are full charged C. keep them in a well-ventilated space D. connect and disconnect them with the supply on
C
5. Impurities in an electrolyte can cause an internal short circuit condition called A. depolarization B. electrolysis C. local action D. polarization
C
5. The magnetism that remains in a magnet after the magnetizing force has been removed is called A. permeability B. induction C. residual D. saturation
C
5.The specific resistance ρ depends upon A.The area of cross-section and the length of the conductor B.The material of the conductor, its area of cross-section and length C. The nature of the material of the conductor only D. The area of cross-section of the conductor
C
6.Iron becomes magnetized by induction when it is A. heated B. suspended east and west C. near to one end of a magnet D. treated with some chemicals
C
6.Which of the following is a vector quantity? A. magnetic potential B. flux density C. magnetic field intensity D. relative permeability
C
7. Magnetic lines of force are called A. hysteresis B. current C. flux D. magnetomotive force
C
8.One factor affecting voltages of the primary cell is the A. area of the plates B. distance between the plates C. types of plates and electrolyte D. thickness of the plates
C
8.Whenever a conductor cuts magnetic flux, an emf is induced in that conductor. This statement is due to A. Joule's law B. Coulomb's law C. Faraday's law D. Weber and Ewing's theory
C
9.The value of Joule's mechanical equivalent of heat, J, is equal to A. 4.2 calories per Joule B. 2.4 Joules per calorie C. 4.2 Joules per calorie D. 4.2 Joules
C
