Physics 212: Engineering Physics 2: Dr. Barber
Which of the following graphs best represents the current-voltage relationship for a device that obeys Ohm's law? A) I B) II C) III D) IV E) V *DIAGRAM ON 2015 TEST PG. 6, #36
II (linear graph with a positive slope y=x)
Three capacitors have capacitances C1 < C2 < C3. If these capacitors are connected in series, which of the followingis true for the resulting equivalent capacitance? a. Ceq < C1 b. Ceq > C3 c. Ceq = (C1 + C2 + C3)/3 d. None of the above is always correct.
Ceq<C1
A step-down transformer is used to: A) increase the power B)decrease the power C)increase the voltage D) decrease the voltage E)change ac to dc
D) decreases the voltage
Upon reflection, light undergoes a 180° phase change: a. always. b. if the incident medium has the higher index of refraction. c. if the incident medium has the lower index of refraction. d. whenever the incident angle is less than the critical angle.
c. If the incident medium has the lower index of refraction
There is a current I flowing in a clockwise direction in a square loop of wire that is in the plane of the paper. If the uniform magnetic field B is toward the right, and if each side of the loop has length L, then the net magnetic force acting on the loop is: a. 2ILB. b. ILB. c. IBL^2. d. zero.
Zero
Displacement current exists wherever there is: A) a magnetic field B)moving charge C)a changing magnetic field D) an electric field E)a changing electric field
a changing electric field
A magnet moving past an object will produce eddy currents in the object if the object: a. is a magnetic material only. b. is a conductor. c. is an insulator. d. is a liquid.
b. Is a conductor
The number of electric field lines passing through a unit cross sectional area is indicative of: a. field direction. b. charge density. c. field strength. d. charge motion.
field strength.
A spherical conducting shell has charge Q. A particle with charge q is placed at the center of the cavity. The charge on the inner surface of the shell and the charge on the outer surface of the shell, respectively, are: A) 0, Q B) q, Q - q C) Q, 0 D) -q, Q + q E) -q, 0
-q, Q + q
The intensity of unpolarized light passing through a single sheet of polarizing material changes by a factor of: a. 1. b. 0.5. c. cos θ. d. cos2θ.
.5
Magnetic field lines produced by a long straight wire carrying a current: A) are in the direction of the current B)are opposite to the direction of the current C)leave the wire radially D) form circles concentric with the wire E)are lines similar to those produced by a bar magnet
form circles concentric with the wire
When a permanent magnet is strongly heated: A) nothing happens B)it becomes an induced magnet C)it loses its magnetism D) its magnetism increases E)its polarity reverses
it loses its magnetism
The image produced by a convex mirror of an object in front of the mirror is always: A) virtual, upright, and larger than the object B)virtual, upright, and smaller than the object C)real, upright, and larger than the object D) real, upright, and smaller than the object E)none of the above
virtual, upright, and smaller than the object
A hollow metal sphere is charged to a potential V. The potential at its center is: A) V B) 0 C) -V D) 2V E) πV
A) V
Bragg's law for x-ray diffraction is 2d sinƟ = mλ, where Ɵ is the angle between the incident beam and: A) a reflecting plane of atoms B)the normal to a reflecting plane of atoms C)the scattered beam D) the normal to the scattered beam E)the refracted beam
A) a reflecting plane of atoms
The natural angular frequency of a certain RLC series circuit is 0. A source of sinusoidal emf, with angular frequency 20, is inserted into the circuit. After transients die out, the angular frequency of the current oscillations is: A) ω(initial)/2 B) ω(initial)0 C) 2ω(initial)0 D) 1.5ω(initial)0 E) 3ω(initial)0
2ω(initial)0
In a certain material, there is a current of 14 A flowing through a surface to the right, and there is an equal amount of positive and negative charge passing through the surface producing the current. How much negative charge passes through the surface? a. 7 C/s toward the right b. 7 C/s toward the left c. 14 C/s toward the right d. 14 C/s toward the left e. 28C/s toward the left
7 C/s toward the left
Evidence for the wave nature of matter is: A) electron diffraction and interference experiments B)Thompson's measurement of e/m C)Young's double slit experiment D) the photoelectric effect E)Lenz's law
A) electron diffraction and interference experiments
A light beam incident on a diffraction grating consists of waves with two different wavelengths. The separation of the two first-order lines is greatest if: A) the dispersion is greater B)the resolution is greater C)the dispersion is smaller D) the resolution is smaller E)none of the above (line separation does not depend on either dispersion or resolution)
A) the dispersion is greater
Which of the following types of electromagnetic radiation travels at the greatest speed in vacuum? A) Radio waves B)Visible light C)X rays D) Gamma rays E)All of these travel at the same speed
All of these travel at the same speed
When the reflection of an object is seen in a convex mirror the image will: a. always be real b. always be virtual. c. may be either real or virtual. d. will always be enlarged.
Always be virtual
The diagram shows two small paramagnetic spheres, one near each end of a bar magnet. Which of the following statements is true? A) The force on 1 is toward the magnet and the force on 2 is away from the magnet B)The force on 1 is away from the magnet and the force on 2 is toward the magnet C)The forces on 1 and 2 are both toward the magnet D) The forces on 1 and 2 are both away from the magnet E)The magnet does not exert a force on either sphere
C) The forces on 1 and 2 are both toward the magnet
A magnetic field CANNOT: A) exert a force on a charge B) accelerate a charge C) change the momentum of a charge D) change the kinetic energy of a charge E) exist
D) change the kinetic energy of a charge
For an electromagnetic wave the direction of the vector {v:E}x{v:B} gives: A) the direction of the electric field B)the direction of the magnetic field C)the direction of wave propagation D) the direction of the electromagnetic force on a proton E)the direction of the emf induced by the wave
C) the direction of wave propagation
A car battery is rated at 80 A * h. An ampere-hour is a unit of: A) power B) energy C) current D) charge E) force
D) Charge
. "The sum of the emf's and potential differences around a closed loop equals zero" is a consequence of: A) Newton's third law B)Ohm's law C)Newton's second law D) conservation of energy E)conservation of charge
D) conservation of energy
Interference of light is evidence that: A) the speed of light is very large B)light is a transverse wave C)light is electromagnetic in character D) light is a wave phenomenon E)light does not obey conservation of energy
D) light is a wave phenomenon
If n_water = 1.50 and n_glass = 1.33, then total internal reflection at an interface between this glass and water: A) occurs whenever the light goes from glass to water B)occurs whenever the light goes from water to glass C)may occur when the light goes from glass to water D) may occur when the light goes from water to glass E)can never occur at this interface
D) may occur when the light goes from water to glass
When a highly coherent beam of light is directed against a very fine wire, the shadow formed behind it is not just that of a single wire but rather looks like the shadow of several parallel wires. The explanation of this involves: A) refraction B) diffraction C) reflection D) Doppler effect E) an optical illusion
B) diffraction
A magnetic field {v:B₀} is applied to a diamagnetic substance. In the interior, the magnetic field produced by the magnetic dipoles of the substance is: A) greater than B₀ and in the opposite direction B)less than B₀ and in the opposite direction C)greater than B₀ and in the same direction D) less than B₀ and in the same direction E)the same as B₀
B) less than B₀ and in the opposite direction
In the formula F = qv x B : A)F must be perpendicular to v but not necessarily to B B)F must be perpendicular to B but not necessarily to v C)v must be perpendicular to B but not necessarily to F D) all three vectors must be mutually perpendicular E)F must be perpendicular to both v and B *vector signs over F, v, and B
F must be perpendicular to both v and B
A current in a long, straight wire produces a magnetic field. The magnetic field lines: a. go out from the wire to infinity. b. come in from infinity to the wire. c. form circles that pass through the wire. d. form circles that go around the wire.
Form circles that go around the wire
In Bragg's law, 2d sin θ = mλ, how is θ measured? a. from the reflecting crystal plane b. from the normal to the reflecting crystal plane c. from the direction of the incident beam d. from the normal to the direction of the incident beam
From the reflecting crystal plane
The diagrams show five possible orientations of a magnetic dipole μ(vector) in a uniform magnetic field B(vector). For which of these does the magnetic torque on the dipole have the greatest magnitude? A) I B) II C) III D) IV E) V *DIAGRAM ON 2015 TEST PG. 8, #48
I
Two point charges are arranged as shown. In which region could a third charge +1 C be placed so that the net electrostatic force on it is zero? A) I only B) I and II only C) III only D) I and III only E) II only *SEE DIAGRAM 2015 FINAL PAGE 3 #12
I only
A magnet moves inside a coil. Consider the following factors: I. strength of the magnet II. number of turns in the coil III. speed at which the magnet moves Which can affect the emf induced in the coil? A) I only B) II only C) III only D) I and II only E) I, II, III
I, II, and III
In a capacitor in an AC circuit, the voltage: a. leads the current by 90°. b. lags the current by 90°. c. may lead or lag the current depending on the frequency. d. is in phase with 70.7% of the current.
Lags the current by 90 degrees
Consider two long, straight parallel wires, each carrying a current I. If the currents are flowing in opposite directions: a. the two wires will attract each other. b. the two wires will repel each other. c. the two wires will exert a torque on each other. d. neither wire will exert a force on the other.
The two wires will repel each other
Light from a stationary spaceship is observed, then the spaceship moves directly away from the observer at high speed. As a result, the light seen by the observer has: A) a higher frequency and a longer wavelength than before B)a lower frequency and a shorter wavelength than before C)a higher frequency and a shorter wavelength than before D) a lower frequency and a longer wavelength than before E)the same frequency and wavelength as before
a lower frequency and a longer wavelength than before
A free electron is in an electric field. With respect to the field, it experiences a force acting: a. parallel. b. anti-parallel. c. perpendicular. d. along a constant potential line.
anti-parallel
A positively charged metal sphere A is brought into contact with an uncharged metal sphere B. As a result: A) both spheres are positively charged B)A is positively charged and B is neutral C)A is positively charged and B is negatively charged D) A is neutral and B is positively charged E)A is neutral and B is negatively charged
both spheres are positively charged
The charge on a glass rod which has been rubbed with silk is called positive: A) by arbitrary convention B)so that the proton charge will be positive C)to conform to the conventions adopted for G and m in Newton's law of gravitation D) because like charges repel E)because glass is an insulator
by arbitrary convention
Consider (I) the law of reflection and (II) the law of refraction. Huygens' principle can be used to derive: A) only I B)only II C)both I and II D) neither I nor II E)the question is meaningless because Huygen's principle is for wave fronts whereas both I and II concern rays
both I and II
The direction of the force on a current-carrying wire located in an external magnetic field is which of the following? a. perpendicular to the current b. perpendicular to the field c. Both choices A and B are valid. d. None of the above are valid.
c. Both choices A and B are valid.
How can a charged object attract an uncharged object made of non-conducting material? a. The uncharged object must somehow gain a like charge. b. The uncharged object must somehow gain an unlike charge. c. The charges in the uncharged object can become polarized. d. Attraction of an insulator is not possible.
c. The charges in the uncharged object can become polarized.
When you flip a switch to turn on a light, the delay before the light turns on is determined by: a. the number of electron collisions per second in the wire. b. the drift speed of the electrons in the wire. c. the speed of the electric field moving in the wire. d. none of these, since the light comes on instantly.
c. The speed of the electric field moving in the wire
"The sum of the currents into a junction equals the sum of the currents out of the junction" is a consequence of: A) Newton's third law B)Ohm's law C)Newton's second law D) conservation of energy E)conservation of charge
conservation of charge
Binoculars and microscopes are frequently made with coated optics by adding a thin layer of transparent material to the lens surface as shown. For minimum reflection of the incident light, one wants: A) constructive interference between waves 1 and 2 B)destructive interference between waves 3 and 4 C)constructive interference between 3 and 4 D) the coating to be more transparent than the lens E)the speed of light in the coating to be less than that in the lens *DIAGRAM ON 2015 TEST PAGE 15, #90
constructive interference between 3 and 4
If a charged particle is moving in a uniform magnetic field, its path can be: a. a straight line. b. a circle. c. a helix. d. any of the above.
d. any of the above (Straight line, circle, or helix)
Doug rubs a piece of fur on a hard rubber rod, giving the rod a negative charge. What happens? a. Protons are removed from the rod. b. Electrons are added to the rod. c. The fur is also charged negatively. d. The fur is left neutral.
electrons are added to the rod
A virtual image is one: A) toward which light rays converge but do not pass through B)from which light rays diverge but do not pass through C)from which light rays diverge as they pass through D) toward which light rays converge and pass through E)with a ray normal to a mirror passing through it
from which light rays diverge but do not pass through
The resolving power of a telescope can be increased by: A) increasing the objective focal length and decreasing the eyepiece focal length B)increasing the lens diameters C)decreasing the lens diameters D) inserting a correction lens between objective and eyepiece E)none of the above
increasing the lens diameters
The internal resistances of an ideal voltmeter and an ideal ammeter are, respectively: a. zero and zero. b. infinite and infinite. c. zero and infinite. d. infinite and zero.
infinite and zero
An object placed outside the focal point of a converging lens will produce an image that is: A) upright and virtual B)inverted and virtual C)upright and real D) inverted and real E)impossible to locate
inverted and real
In a purely resistive circuit the current: A) leads the voltage by 1/4 cycle B)leads the voltage by 1/2 cycle C)lags the voltage by 1/4 cycle D) lags the voltage by 1/2 cycle E)is in phase with the voltage
is in phase with the voltage
In a conductor carrying a current we expect the electron drift speed to be: A) much greater than the average electron speed B)much less than the average electron speed C)about the same as the average electron speed D) less than the electron speed at low temperature and greater than the electron speed at high temperature E)less than the electron speed at high temperature and greater than the electron speed at low temperature
much less than the average electron speed
An ion is released from rest and moves, due to the force from an electric field, from a position in the field having apotential of 14 V to a position having a potential of 8 V. The ion: a. must have a positive charge. b. must have a negative charge. c. can have either a positive or a negative charge. d. must be neutral.
must have a positive charge
When a hard rubber rod is given a negative charge by rubbing it with wool: A) positive charges are transferred from rod to wool B)negative charges are transferred from rod to wool C)positive charges are transferred from wool to rod D) negative charges are transferred from wool to rod E)negative charges are created and stored on the rod
negative charges are transferred from wool to rod
As used in the definition of electric field, a "test charge": A) has zero charge B)has charge of magnitude 1 C C)has charge of magnitude 1.6 X 10-19 C D) must be an electron E)none of the above
none of the above
Consider some material that has been cooled until it has become a superconductor. If it is cooled even further, its resistance will: a. increase. b. decrease. c. stay constant and non-zero. d. None of the above.
none of the above
The time constant RC has units of: A) second/farad B) second/ohm C) 1/second D) second/watt E) none of these
none of these
A concave refracting surface is one with a center of curvature: A) to the left of the surface B)to the right of the surface C)on the side of the incident light D) on the side of the refracted light E)on the side with the higher index of refraction
on the side of the incident light
The electric field due to a uniform distribution of charge on a spherical shell is zero: A) everywhere B)nowhere C)only at the center of the shell D) only inside the shell E)only outside the shell
only inside the shell
The emf of a real battery is equal to the potential difference between its terminals: A) under all conditions B)only when the battery is being charged C)only when a large current is in the battery D) only when there is no current in the battery E)under no conditions
only when there is no current in the battery
An electron traveling north enters a region where the electric field is uniform and points north. The electron: A) speeds up B)slows down C)veers east D) veers west E)continues with the same speed in the same direction
slows down
A wire carrying a large current i from east to west is placed over an ordinary magnetic compass. The end of the compass needle marked "N" will point: A) north B)south C)east D) west E)the compass will act as an electric motor, hence the needle will keep rotating
south
A charge, +Q, is placed inside a balloon and the balloon is inflated. As the radius of the balloon r increases, the number of field lines going through the surface of the balloon: a. increases proportional to r2. b. increases proportional to r. c. stays the same. d. decreases as 1/r.
stays the same.
The rms value of an ac current is: A) its peak value B)its average value C)that steady current that produces the same rate of heating in a resistor D) that steady current that will charge a battery at the same rate E)zero
that steady current that produces the same rate of heating in a resistor
The electric field associated with a uniformly charged hollow metallic sphere is the greatest at: a. the center of the sphere. b. the sphere's inner surface. c. infinity. d. the sphere's outer surface.
the sphere's outer surface.
Which of the following electromagnetic radiations has photons with the greatest energy? A) blue light B) yellow light C) x-rays D) radio waves E) microwaves
x-rays
Q1 has 50 electric field lines radiating outward, and Q2 has 150 converging inward. What is the ratio Q1/Q2? a. 3 b. −3 c. 1/3 d. −1/3 e. 0
-1/3
Three polarizing sheets are placed in a stack with the polarizing directions of the first and third perpendicular to each other. What angle could the polarizing direction of the middle sheet make with the polarizing direction of the first sheet to obtain zero transmitted intensity when unpolarized light is incident on the stack? A) 0 B) 30 C) 45 D) 60 E) all angles allow light to pass through
0 degrees
In a Young's experiment, the paths from the slits to a point on the screen differ in length causing constructive interference at the point. Which of the following path-length differences would cause this constructive interference? a. 5λ/2 b. 3λ/4 c. 4λ d. None of the above.
4λ
The force on a charged particle, created by its motion in a magnetic field, is maximum at what angle between the particle velocity and field? a. zero b. 180° c. 90° d. 45°
90 degrees
Two electrons (e1 and e2) and an proton (p) lie on a straight line, as shown. The directions of the force of e2 on e1, the force of p on e1, and the total force on e1, respectively, are: Diagram looks like: -------(e1)--------------(e2)-----------------P-------- A) -->, <-- , --> B) <--, -->, --> C) -->, <--, <-- D) <--, --> , <-- E) <--, <--, <--
<-- , --> , <-- (Left, Right, Left)
The magnetic pole of the Earth nearest the geographic North Pole corresponds to which of the following? a. a magnetic north pole b. a magnetic south pole c. a magnetic arctic pole d. a magnetic Antarctic pole
A magnetic south pole
In the straight-ahead direction (θ = 0°) in single-slit diffraction, which of the following is observed on the screen? a. a minimum equal in width to the adjacent minima b. a minimum double in width to the adjacent minima c. a maximum equal in width to the adjacent maxima d. a maximum double in width to the adjacent maxima
A maximum double in width to the adjacent maxima
Two conducting spheres, one having twice the diameter of the other, are separated by a distance large compared to their diameters. The smaller sphere (1) has charge q and the larger sphere (2) is uncharged. If the spheres are connected by a long thin wire: A) 1 and 2 have the same potential B)2 has twice the potential of 1 C)2 has half the potential of 1 D) 1 and 2 have the same charge E)all of the charge is dissipated
A) 1 and 2 have the same potential
According to Einstein, increasing the brightness of a beam of light without changing its color will increase: a. the number of photons. b. the energy of each photon. c. the speed of the photons. d. the frequency of the photons.
A. the number of photons
In the diagram R1 > R2 > R3. Rank the three resistors according to the current in them, least to greatest. A) 1, 2, 3 B) 3, 2, 1 C) 1, 3, 2 D) 3, 1, 2 E) All are the same *DIAGRAM ON 2015 TEST PAGE 7, #38
ALL are the same
In a certain region of space the electric potential increases uniformly from east to west and does not vary in any other direction. The electric field: A) points east and varies with position B) points east and does not vary with position C)points west and varies with position D) points west and does not vary with position E)points north and does not vary with position
B) points east and does not vary with position
When light passes from air to glass, it bends: A) toward the normal without changing speed B)toward the normal and slows down C)toward the normal and speeds up D) away from the normal and slows down E)away from the normal and speeds up
B) toward the normal and slows down
A long straight wire is in the plane of a rectangular conducting loop. The straight wire carries an increasing current in the direction shown. The current in the rectangle is: A) zero B)clockwise C)counterclockwise D) clockwise in the left side and counterclockwise in the right side E)counterclockwise in the left side and clockwise in the right side *DIAGRAM ON 2015 TEST PG. 10, #59
C) counterclockwise
The current is zero in a conductor when no potential difference is applied because: A) the electrons are not moving B)the electrons are not moving fast enough C)for every electron with a given velocity there is another with a velocity of equal magnitude and opposite direction D) equal numbers of electrons and protons are moving together E)otherwise Ohm's law would not be valid
C) for every electron with a given velocity there is another with a velocity of equal magnitude and opposite direction
In the equation d sinθ= mλ for the lines of a diffraction grating, d is: A) the number of rulings B)the slit width C)the grating spacing D) the order of the line E)the index of refraction
C)the grating spacing
Capacitors C1 and C2 are connected in parallel. Their equivalent capacitance is given by: A) C1C2/(C1 + C2) B) (C1 + C2)/C1C2 C) 1/(C1 + C2) D) C1/C2 E) C1 + C2
C1 + C2
Resonance occurs in an AC series circuit when which of the following conditions is met? a. resistance equals capacitive reactance b. resistance equals inductive reactance c. capacitive reactance equals inductive reactance d. capacitive reactance equals zero
Capacitive reactance equals inductive reactance
Maxwell developed his theory of electromagnetism by combining previous discoveries. He added his own original hypothesis that: a. electric charges produce electric fields. b. moving electric charges produce magnetic fields. c. changing electric fields produce magnetic fields. d. changing magnetic fields produce electric fields.
Changing electric fields produce magnetic fields
A repelling force must occur between two charged objects under which condition? a. Charges are of unlike signs. b. Charges are of like signs. c. Charges are of equal magnitude. d. Charges are of unequal magnitude.
Charges are of like signs.
A bar magnet is falling through a loop of wire with constant velocity. The north pole enters first. As the south pole leaves the loop of wire, the induced current (as viewed from above) will be: a. clockwise. b. counterclockwise. c. zero. d. along the length of the magnet.
Clockwise
In the experiment shown: A) there is a steady reading in G as long as S is closed B)a motional emf is generated when S is closed C)the current in the battery goes through G D) there is a current in G just after S is opened or closed E)since the two loops are not connected, the current in G is always zero *DIAGRAM ON 2015 TEST PG. 9, #55
D) there is a current in G just after S is opened or closed
When you stand in front of a plane mirror, your image is: A) real, upright, and smaller than you B)real, upright, and the same size as you C)virtual, upright, and smaller than you D) virtual, upright, and the same size as you E)real, inverted, and the same size as you
D) virtual, upright, and the same size as you
Which of the following graphs represents the magnitude of the electric field as a function of the distance from the center of a solid charged conducting sphere of radius R? A) A B) B C) C D) D E) E *SEE DIAGRAM ON 2015 TEST PG. 3, #14
E
Choose the INCORRECT statement: A) Gauss' law can be derived from Coulomb's law B)Gauss' law states that the net number of lines crossing any closed surface in an outward direction is proportional to the net charge enclosed within the surface C)Coulomb's law can be derived from Gauss' law and symmetry D) Gauss' law applies to a closed surface of any shape E)If a closed surface encloses no charge, the electric field is zero everywhere on the surface
E) If a closed surface encloses no charge, the electric field is zero everywhere on the surface
In a photoelectric effect experiment the stopping potential is: A) the energy required to remove an electron from the sample B)the kinetic energy of the most energetic electron ejected C)the potential energy of the most energetic electron ejected D) the photon energy E)the electric potential that causes the electron current to vanish
E) the electric potential that causes the electron current to vanish
In an overhead straight wire, the current is north. The magnetic field due to this current, at our point of observation, is: A) east B) up C) north D) down E) west
E) west
Case 1: An electron is released from rest in a uniform electric field. Case 2: A proton is released from rest in a uniform electric field of the same magnitude as in case 1. How does the electric potential energy of the charge-field system behave in these cases? a. In both cases, the potential energy increases. b. In both cases, the potential energy decreases. c. In case 1 the potential energy increases, but in case 2 it decreases. d. In case 1 the potential energy decreases, but in case 2 it increases.
In both cases, the potential energy increases.
Inserting a dielectric material between two charged parallel conducting plates, originally separated by air and disconnected from a battery, will produce what effect on the capacitor? a. increase charge b. increase voltage c. increase capacitance d. decrease capacitance
Increase capacitance
In order of increasing frequency, which of the following is correct? a. visible, radio, ultraviolet, and x-ray b. infrared, visible, ultraviolet, and gamma c. visible, gamma, ultraviolet, and x-ray d. infrared, x-ray, visible, and gamma
Infrared, visible, ultraviolet, and gamma
Electrons are going around a circle in a counterclockwise direction as shown. At the center of the circle they produce a magnetic field that is: A) into the page B) out of the page C) to the left D) to the right E) zero
Into the page
A soft magnetic material has which property? a. It cannot be magnetized. b. It is easy to magnetize. c. It is hard to magnetize. d. It attracts slowly moving charges.
It is easy to magnetize
Electrical charges and magnetic poles have many similarities, but one difference is: a. opposite magnetic poles repel. b. magnetic poles cannot induce magnetic poles in other materials. c. a magnetic pole cannot be isolated. d. magnetic poles do not produce magnetic fields.
Magnetic pole cannot be isolated
Dispersion occurs when: a. some materials bend light more than other materials. b. a material slows down some wavelengths more than others. c. a material changes some frequencies more than others. d. light has different speeds in different materials.
Material slows down some wavelengths more than others
The basic function of the electric generator is which of the following conversion processes? a. mechanical energy to electrical b. electrical energy to mechanical c. low voltage to high or vice versa d. alternating current to direct
Mechanical energy to electrical
If a certain resistor obeys Ohm's law, its resistance will change: a. as the voltage across the resistor changes. b. as the current through the resistor changes. c. as the energy given off by the electrons in their collisions changes. d. none of the above, since resistance is a constant for the given resistor.
None of the above
A light ray incident on the interface between air and glass can undergo total internal reflection: a. only in the glass. b. only in the air. c. in either the glass or the air. d. in the air only if the index of refraction of the glass is greater than .
Only in the glass
According to Lenz's law, the direction of an induced current in a conductor will be that which tends to produce whichof the following effects? a. enhance the effect which produces it b. produce a greater heating effect c. produce the greatest voltage d. oppose the effect which produces it
Oppose the effect which produces it
Which of the following describes what will happen to a light ray incident on an air-to-glass boundary? a. total reflection b. total transmission c. partial reflection, partial transmission d. partial reflection, total transmission
Partial reflection, partial transmission
Let Q denote charge, V denote potential difference, and U denote stored energy. Of these quantities, capacitors in series must have the same: A) Q only B) V only C) U only D) Q and U only E) V and U only
Q only
A capacitor "has a charge Q". The actual charges on its plates are: A) Q, Q B) Q/2, Q/2 C) Q, -Q D) Q/2, -Q/2 E) Q, 0
Q, -Q
Which two resistors are in parallel with each other? a. R and R4 b. R2 and R3 c. R2 and R4 d. R and R1 *DIAGRAM ON 2016 TEST PG. 4, #30
R2 and R3
If R1 < R2 < R3, and if these resistors are connected in series in a circuit, which one dissipates the greatest power? a. R1 b. R2 c. R3 d. All are equal in power dissipation.
R3
In an ideal case, rays coming from an object toward a lens or mirror should be reasonably close to the central axis. Tothe extent that this condition is not completely met, which one of the following effects occurs? a. spherical aberration b. mirages c. chromatic aberration d. light scattering
Spherical aberration
A charged capacitor and an inductor are connected in series. At time t = 0 the current is zero, but the capacitor is charged. If T is the period of the resulting oscillations, the next time, after t = 0, that the charge on the capacitor is a maximum is: A) T B) T/4 C) T/2 D) 2T E) 3T
T/2
Two beams of coherent light are shining on the same piece of white paper. With respect to the crests and troughs of such waves, darkness will occur on the paper where: a. the crest from one wave overlaps with the crest from the other. b. the crest from one wave overlaps with the trough from the other. c. the troughs from both waves overlap. d. darkness cannot occur as the two waves are coherent.
The crest from one wave overlaps with the trough from the other
A current in a solenoid coil creates a magnetic field inside that coil. The field strength is directly proportional to: a. the coil area. b. the current. c. Both A and B are valid choices. d. None of the above choices are valid.
The current
The diagram shows an inductor that is part of a circuit. The direction of the emf induced in the inductor is indicated. Which of the following is possible? A) The current is constant and rightward B)The current is constant and leftward C)The current is increasing and rightward D) The current is increasing and leftward E)None of the above *DIAGRAM ON TEST 2015 PAGE 10, #60
The current is increasing and leftward
Which of the following primarily determines the resolving power of a telescope? a. the barrel length b. the focal length of the objective lens c. the diameter of the objective lens d. the thickness of the eyepiece
The diameter of the objective lens
Kirchhoff's rules are the junction rule and the loop rule. Which of the following statements is true? a. Both rules are based on the conservation of charge. b. Both rules are based on the conservation of energy. c. The junction rule is based on conservation of charge, and the loop rule is based on conservation of energy. d. The junction rule is based on conservation of energy, and the loop rule is based on conservation of charge.
The junction rule is based on the conservation of charge, and the loop rule is based on the conservation of energy.
A stationary positive charge +Q is located in a uniform magnetic field B, which is directed toward the right as indicated. The direction of the magnetic force on Q is: a. toward the right. b. up. c. down. d. There is no magnetic force. *DIAGRAM ON TEST 2016 PG. 4, #35
There is no magnetic force.
Two capacitors, with CA greater than CB, are connected in parallel with a battery. Which of the following is true? a. There is more potential difference across CA. b. There is more potential difference across CB. c. There is the same charge stored on each capacitor. d. There is the same potential difference across both capacitors.
There is the same potential difference across both capacitors
In an oscillating LC circuit, the total stored energy is U. The maximum energy stored in the capacitor during one cycle is: A) U/2 B) 2U C) U D) U/(2π) E) U/π
U
Which of the following best describes the image from a plane mirror? a. virtual and magnification greater than one b. real and magnification less than one c. virtual and magnification equal to one d. real and magnification equal to one
Virtual and magnification equal to one
Which of the following best describes the image of a concave mirror when the object's distance from the mirror isless than the focal point distance? a. virtual, upright, and magnification greater than one b. real, inverted, and magnification less than one c. virtual, upright, and magnification less than one d. real, inverted, and magnification greater than one
Virtual, upright, and magnification greater than one
The diagram shows the electric field lines in a region of space containing two small charged spheres (Y and Z). Then: A)Y is negative and Z is positive B)the magnitude of the electric filed is the same everywhere C)the electric field is strongest midway between Y and Z D)Y is positive and Z is negative E)Y and Z must have the same sign *SEE DIAGRAM ON 2015 FINAL PAGE 2 #8
Y is positive and Z is negative
In a Young's double-slit experiment the center of a bright fringe occurs wherever waves from the slits differ in the distance they travel by a multiple of: A) a fourth of a wavelength B)a half a wavelength C)a wavelength D) three-fourths of a wavelength E)none of the above
a wavelength
Who proposed that diffraction of light around a small disk could create a bright spot behind the disk, at the center, where classically a shadow should be? a. Fresnel b. Young c. Newton d. Bragge. Huygens
a. Fresnel
The Doppler shift for electromagnetic radiation from distant galaxies moving away from the observer is called a: a. red shift. b. blue shift. c. black shift. d. vacuum shift.
a. red shift
In a circuit made up of an inductor, resistor, ammeter, battery, and switch in series, at which of the following times after the switch is closed is the rate of current increase greatest? a. zero b. one time constant c. reciprocal of one time constant d. ten time constants
a. zero
A 10-V-emf battery is connected in series with the following: a 2-μF capacitor, a 2-Ω resistor, an ammeter, and a switch, initially open; a voltmeter is connected in parallel across the capacitor. After the switch has been closed for a relatively long period (several seconds, say), what are the current and capacitor voltage readings, respectively? a. zero A, 10 V b. zero A, zero V c. 5 A, zero V d. 5 A, 10 V *DIAGRAM ON 2016 TEST PG. 4, # 32
a. zero A, 10 V
As a monochromatic light ray is transmitted through an air-to-glass boundary, what happens to the wavelength? a. increases b. decreases c. remains unchanged d. approaches zero
b. decreases
The rms current is equal to the direct current that: a. produces the same average voltage across a resistor as in an AC circuit. b. dissipates energy in a resistor at the same average rate as in an AC circuit. c. provides the same average current in a resistor as in an AC circuit. d. results in the same peak power in a resistor as in an AC circuit.
b. dissipate energy into resister at the same average rate as in an AC circuit
The electric field at the surface of a positively charged conductor has a direction characterized by which of the following? a. tangent to the surface b. perpendicular inward c. at a 45° angle to the surface d. perpendicular outward
b. perpendicular outward
74. Blue light will not eject electrons from a certain metal; however, which one of the following may possibly eject electrons from that metal? a. infrared b. ultraviolet c. red d. green
b. ultraviolet
Two capacitors, with CA greater than CB, are connected in series with a battery. Which of the following is true? a. There is more charge stored on CA. b. There is more charge stored on CB. c. There is the same charge stored on each capacitor. d. There is the same potential difference across both capacitors.
c. There is the same charge stored on each capacitor.
Consider two charged spheres, one with charge +2 C and the other with −2 C. A proton is at the point half-way between the spheres. What is not zero? a. the potential energy of the proton b. the work to move the proton from infinity to that point c. the force on the proton d. all of the three above are zero
c. the force on the proton
The cardboard center of a paper towel roll: A) is a possible Gaussian surface B)cannot be a Gaussian surface because there is no charge in it C)cannot be a Gaussian surface because it does not fully enclose a volume D) cannot be a Gaussian surface since it is an insulator E)none of the above
cannot be a Gaussian surface because it does not fully enclose a volume
The term "virtual" as applied to an image made by a mirror means that the image: A) is on the mirror surface B)cannot be photographed by a camera C)is in front of the mirror D) is the same size as the object E)cannot be shown directly on a screen
cannot be shown directly on a screen
A square loop of wire lies in the plane of the page. A decreasing magnetic field is directed into the page. The induced current in the loop is: A) counterclockwise B)clockwise C)zero D) up the left edge and from right to left along the top edge E)through the middle of the page
clockwise
The equipotential surfaces associated with a charged point particle are: A) radially outward from the particle B)vertical planes C)horizontal planes D) concentric spheres centered at the particle E)concentric cylinders with the particle on the axis
concentric spheres centered at the particle
The blue tint of a coated camera lens is largely caused by what effect? a. diffraction b. refraction c. polarization d. interference
d. Interference
Two loops of wire are arranged along a common axis so that a changing current in one induces a current in the other.If the current in the first is increasing clockwise by 1.0 A each second, the induced current in the second loop will: a. be increasing counterclockwise. b. stay constant. c. increase clockwise also. d. stay zero.
d. Stay constant
Which of the following best characterizes electrical conductors? a. low mass density b. high tensile strength c. electric charges move freely d. poor heat conductors
electric charges move freely
The magnetic properties of materials stem chiefly from: A) particles with north poles B)particles with south poles C)motions of protons within nuclei D) proton spin angular momentum E)electron magnetic dipole moments
electron magnetic dipole moments
Select the correct statement: A) ultraviolet light has a longer wavelength than infrared B)blue light has a higher frequency than x rays C)radio waves have higher frequency than gamma rays D) gamma rays have higher frequency than infra-red waves E)electrons are a type of electromagnetic wave
gamma rays have higher frequency than infra-red waves
Radio waves are readily diffracted around buildings where as light waves are negligibly diffracted around buildings. This is because radio waves: A) are plane polarized B)have much longer wavelengths than light waves C)have much shorter wavelengths than light waves D) are nearly monochromatic (single frequency) E)are amplitude modulated (AM)
have much longer wavelengths than light waves
A magnetic field exerts a force on a charged particle: A) always B)never C)if the particle is moving across the field lines D) if the particle is moving along the field lines E)if the particle is at rest
if the particle is moving across the field lines
An electron moves in the negative x direction, through a uniform magnetic field in the negative y direction. The magnetic force on the electron is: A) in the negative x direction B)in the positive y direction C)in the negative y direction D) in the positive z direction E)in the negative z direction *DIAGRAM ON 2015 TEST PG. 8, #44
in the negative z direction
Increasing the voltage across the two plates of a capacitor will produce what effect on the capacitor? a. increase charge b. decrease charge c. increase capacitance d. decrease capacitance
increase charge
An uncharged conductor is supported by an insulating stand. I pass a positively charged rod near the left end of the conductor, but do not touch it. The right end of the conductor will be: a. negative. b. positive. c. neutral. d. attracted.
positive
A dielectric slab is slowly inserted between the plates of a parallel plate capacitor, while the potential difference between the plates is held constant by a battery. As it is being inserted: A) the capacitance, the potential difference between the plates, and the charge on the positive plate all increase B)the capacitance, the potential difference between the plates, the charge on the positive plate all decrease C)the potential difference between the plates increases, the charge on the positive plate decreases, and the capacitance remains the same D) the capacitance and the charge on the positive plate decrease but the potential difference between the plates remains the same E)the capacitance and the charge on the positive plate increase but the potential difference between the plates remains the same
the capacitance and the charge on the positive plate increase but the potential difference between the plates remains the same
The magnetic field B inside a long ideal solenoid is independent of: A) the current B)the core material C)the number of windings per unit length D) the cross-sectional area E)the direction of the current
the cross-sectional area
Conduction electrons move to the right in a certain wire. This indicates that: A) the current density and electric field both point right B)the current density and electric field both point left C)the current density points right and the electric field points left D) the current density points left and the electric field points right E)the current density points left but the direction of the electric field is unknown
the current density and electric field both point left
The energy of a magnetic dipole in an external magnetic field is least when: A) the dipole moment is parallel to the field B)the dipole moment is antiparallel to the field C)the dipole moment is perpendicular to the field D) none of the above (the same energy is associated with all orientations) E)none of the above (no energy is associated with the dipole-field interaction)
the dipole moment is parallel to the field
If the charge on a parallel-plate capacitor is doubled: A) the capacitance is halved B)the capacitance is doubled C)the electric field is halved D) the electric field is doubled E)the surface charge density stays the same
the electric field is doubled
An electron volt is: A) the force acting on an electron in a field of 1 N/C B)the force required to move an electron 1 meter C)the energy gained by an electron in moving through a potential difference of 1 volt D) the energy needed to move an electron through 1 meter in any electric field E)the work done when 1 coulomb of charge is moved through a potential difference of 1 volt
the energy gained by an electron in moving through a potential difference of 1 volt
If a charge +Q is placed inside a hollow isolated conductor that is originally neutral, and the charge does not touch that conductor at any time: a. the inside surface of the conductor will become positively charged. b. the outside surface of the conductor will become positively charged. c. both the inner and outer surfaces will remain neutral. d. both the inner and outer surfaces will become negative.
the outside surface of the conductor will become positively charged.
A point charge is placed at the center of a spherical Gaussian surface. The total electric flux φE through the closed surface is changed if: A) the sphere is replaced by a cube of the same volume B)the sphere is replaced by a cube of one-tenth the volume C)the point charge is moved off center (but still inside the original sphere) D) the point charge is moved to just outside the sphere E)a second point charge is placed just outside the sphere
the point charge is moved to just outside the sphere
A battery is connected across a parallel combination of two identical resistors. If the potential difference across the terminals is V and the current in the battery is i, then: A) the potential difference across each resistor is V and the current in each resistor is i B)the potential difference across each resistor is V/2 and the current in each resistor is i/2 C)the potential difference across each resistor is V and the current in each resistor is i/2 D) the potential difference across each resistor is V/2 and the current in each resistor is i E)none of the above are true
the potential difference across each resistor is V and the current in each resistor is i/2
There is a hollow, conducting, uncharged sphere with a negative charge inside the sphere. Consider the electrical potential at the inner and outer surfaces of the sphere. Which of the following is true? a. The potential on the inner surface is greater .b. The potential on the outer surface is greater. c. The potentials on both surfaces are zero. d. The potentials on both surfaces are equal but not zero.
the potentials on both surfaces are equal but not zero
Faraday's law states that an induced emf is proportional to: A) the rate of change of the magnetic field B)the rate of change of the electric field C)the rate of change of the magnetic flux D) the rate of change of the electric flux E)zero
the rate of change of the magnetic flux
An electron moves from point i to point f, in the direction of a uniform electric field. During this displacement: A) the work done by the field is positive and the potential energy of the electron-field system increases B)the work done by the field is negative and the potential energy of the electron-field system increases C)the work done by the field is positive and the potential energy of the electron-field system decreases D) the work done by the field is negative and the potential energy of the electron-field system decreases E)the work done by the field is positive and the potential energy of the electron-field system does not change
the work done by the field is negative and the potential energy of the electron-field system increases
If two light waves are coherent: A) their amplitudes are the same B)their frequencies are the same C)their wavelengths are the same D) their phase difference is constant E)the difference in their frequencies is constant
their phase difference is constant
A neutral metal ball is suspended by a string. A positively charged insulating rod is placed near the ball, which is observed to be attracted to the rod. This is because: A) the ball becomes positively charged by induction B)the ball becomes negatively charged by induction C)the number of electrons in the ball is more than the number in the rod D) the string is not a perfect insulator E)there is a rearrangement of the electrons in the ball
there is a rearrangement of the electrons in the ball
Of the following choices, the copper conductor that has the least resistance is: A) thin, long, and hot B)thick, short, and cool C)thick, long, and hot D) thin, short, and cool E)thin, short, and hot
thick, short, and cool
An electrical insulator is a material: A) containing no electrons B)through which electrons do not flow easily C)which has more electrons than protons on its surface D) cannot be a pure chemical element E)must be a crystal
through which electrons do not flow easily
The reason there are two slits, rather than one, in a Young's experiment is: A) to increase the intensity B)one slit is for frequency, the other for wavelength C)to create a path length difference D)one slit is for E(vector) fields, the other is for B(vector fields E)two slits in parallel offer less resistance
to create a path length difference
Assume that a uniform magnetic field is directed into this page. If an electron is released with an initial velocity directed from the bottom edge to the top edge of the page, which of the following describes the direction of the resultant force acting on the electron? a. out of the page b. to the right c. to the left d. into the page
to the right
Magnetic field lines inside the solenoid shown are: A) clockwise circles as one looks down the axis from the top of the page B)counterclockwise circles as one looks down the axis from the top of the page C)toward the top of the page D) toward the bottom of the page E)in no direction since B = 0 *DIAGRAM ON 2015 TEST PG. 9, #54
toward the top of the page
A 2-μF and a 1-μF capacitor are connected in parallel, and a potential difference is applied across the combination. The 2-μF capacitor has: A) twice the charge of the 1-μF capacitor B)half the charge of the 1-μF capacitor C)twice the potential difference of the 1-μF capacitor D) half the potential difference of the 1-μF capacitor E)none of the above
twice the charge of the 1-μF capacitor
Two charges, +Q and −Q, are located two meters apart, and there is a point along the line that is equidistant from the two charges as indicated. Which vector best represents the direction of the electric field at that point? a. Vector EA b. Vector EB c. Vector EC d. The electric field at that point is zero. *DIAGRAM ON 2016 TEST PAGE 1, #7
vector E_A
A spherical surface surrounds a point charge at its center. If the charge is doubled and if the radius of the surface is also doubled, what happens to the electric flux ΦE out of the surface and the magnitude E of the electric field at the surface as a result of these doublings? a. ΦE and E do not change. b. ΦE increases and E remains the same. c. ΦE increases and E decreases. d. ΦE increases and E increases.
ΦE increases and E decreases.
The diagram shows a particle with positive charge Q and a particle with charge -Q. The electric field at point P on the perpendicular bisector of the line joining them is: -Q* | | |_________________xP | | | +Q* A) ↑ B) ↓ C) → D) ← E) zero *SEE DIAGRAM ON 2015 FINAL PAGE 2 #10
↑
The diagram shows a straight wire carrying a flow of electrons into the page. The wire is between the poles of a permanent magnet. The direction of the magnetic force exerted on the wire is: A) ↑ B) ↓ C) ← D) → E) into the page *DIAGRAM ON 2015 TEST PG. 8 , #47
↑
Positive charge Q is uniformly distributed on a semicircular rod. What is the direction of the electric field at point P, the center of the semicircle? A) ↑ B) ↓ C) ← D) → E) ↗
→