Download Sample Mid-Term 4

Review Questions
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) If a compass is moved from the northern hemisphere to the southern hemisphere, its magnetic
needle will change direction
1)
A) by 90 degrees.
B) depending on where the measurement is taken.
C) hardly at all.
D) by 180 degrees.
E) none of these
2) When there is a change in the magnetic field in a closed loop of wire
2)
A) a voltage is induced in the wire.
B) electromagnetic induction occurs.
C) a current is created in the loop of wire.
D) all of these
E) none of these
3) Electromagnetic waves can travel
3)
A) through a vacuum.
B) through a medium.
C) through either a medium or a vacuum.
4) An electron is shot through a spot somewhere between the ends of a horseshoe magnet. The
electron
4)
A) is unaffected by the field.
B) is repelled by both poles, and therefore is turned back.
C) is attracted to one of the poles, and repelled by the other.
D) speed is increased.
E) direction is changed.
5) Connect a pair of lamps in series and you draw current from the connected battery. Connect the
same lamps in parallel and you draw
A) more current.
B) less current.
C) the same current.
D) sometimes more, sometimes less.
6) Moving electric charges will interact with
5)
6)
A) only a magnetic field.
B) an electric field or a magnetic field.
C) only an electric field.
D) none of these
7) An electric motor is very similar to
7)
A) an automobile battery.
B) an electric generator.
C) a radio receiver.
D) None of the above choices are correct.
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8) A woman experiences an electrical shock. The electrons making the shock come from the
8)
A) woman's body.
B) hairdryer.
C) power plant.
D) electric field in the air.
E) ground.
9) A positive charge and a negative charge held near each other are released. As they move, the force
on each particle
A) decreases.
B) increases.
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C) stays the same.
10) The cones in the retina of the eye are
10)
A) concentrated along the periphery of vision.
B) uniformly spread along the visual field.
C) most densely packed at the center of vision.
11) If a steady magnetic field exerts a force on a moving charge, that force is directed
11)
A) opposite the motion.
B) in the direction of the motion.
C) at right angles to the direction of the motion.
12) The critical angle for a transparent material is the angle at and beyond which all light within the
material is
A) absorbed.
B) refracted.
C) dispersed.
D) reflected.
12)
E) diffused.
13) To say that electric charge is conserved is to say that electric charge
13)
A) is sometimes negative.
B) can be neither created nor destroyed.
C) is a whole number multiple of the charge of one electron.
D) may occur in an infinite variety of quantities.
E) will interact with neighboring electric charges.
14) If you walk towards a mirror at a certain speed, the relative speed between you and your image is
A) your speed.
B) twice your speed.
C) half your speed.
D) none of these
15) An uncharged pith ball is suspended by a nylon fiber. When a negatively charged rubber rod is
brought nearby, without touching it, the pith ball
A) becomes charged by induction.
B) is repelled by the rod.
C) becomes polarized.
D) in unaffected.
E) None of the above choices are correct.
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14)
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16) An iron rod becomes magnetic when
16)
A) its electrons stop moving and point in the same direction.
B) its atoms are aligned having plus charges on one side and negative charges on the other.
C) the net spins of its electrons are in the same direction.
D) positive ions accumulate at one end and negative ions at the other end.
E) none of these
17) Which pole of a compass needle points to a south pole of a magnet?
A) south pole
B) north pole
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C) both of these
18) Electric power can be transmitted from one place to another without the need for connecting wires
in between. This statement is
A) sometimes true.
B) always true.
18)
C) always false.
19) The electrical force between charges is strongest when the charges are
19)
A) far apart.
B) close together.
C) The electric force is constant everywhere.
20) Electrons are made to flow in a wire when there is
20)
A) a potential difference across its ends.
B) more potential energy at one end of the wire than the other.
C) an imbalance of charges in the wire.
21) When we say an appliance "uses up electricity," we really are saying that
21)
A) electrons are taken out of the circuit and put somewhere else.
B) electron kinetic energy is changed into heat.
C) electric charges are dissipated.
D) the main power supply voltage is lowered.
E) current disappears.
22) Strip electrons from an atom and the atom becomes a
22)
A) different element.
B) positive ion.
C) molecule.
D) negative ion.
23) Magnetic compasses apparently were first used by
23)
A) Vikings.
B) Australian aborigines.
C) Greeks.
D) Columbus.
E) Chinese.
24) When a bar magnet is thrust into a coil of copper wire, the coil tends to
A) repel the magnet as it enters.
B) attract the magnet as it enters.
C) both of these
D) neither of these
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24)
25) The image of the "infinitely-far-away" sun produced by a converging lens appears
25)
A) beyond the focal point.
B) at the focal point.
C) between the lens and the focal point.
26) A circuit breaker often serves the same purpose as a
26)
A) fuse.
B) capacitor.
C) battery
D) All of the above choices are correct.
E) None of the above choices are correct.
27) Magnetic field lines about a current-carrying wire
27)
A) circle the wire in closed loops.
B) extend radially from the wire.
C) Choices A and B are both correct.
D) None of the above choices are correct.
28) Thrust a magnet into a coil of wire and the coil
28)
A) becomes an electromagnet.
B) has a current in it.
C) both of these
D) neither of these
29) An ampere is a unit of electrical
29)
A) current.
B) pressure.
C) resistance.
D) all of these
E) none of these
30) Which force field can increase a moving electron's speed?
A) only a magnetic field
B) only an electric field
C) either an electric or magnetic field
D) none of these
30)
31) In the periphery of our vision, we are
31)
A) more sensitive to low frequencies than high ones.
B) sensitive to both movement and color.
C) sensitive to movement, but cannot see color.
D) insensitive to color and movement.
E) none of these
32) In the unlikely case of a lightning strike, it is worse to be inside a building framed with
A) steel.
B) wood.
C) aluminum.
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D) iron.
32)
33) Information-carrying nerves are connected to the retina at
33)
A) the fovea.
B) the iris.
C) the periphery.
D) the blind spot.
E) the cornea.
34) In an electrically neutral atom the number of protons in the nucleus is equal to the number of
A) electrons that surround the nucleus.
B) neutrons in the nucleus.
C) Choices A and B are both correct.
D) Choices A and B are both incorrect.
35) The source of all magnetism is
34)
35)
A) tiny domains of aligned atoms.
B) moving electric charge.
C) ferromagnetic materials.
D) tiny pieces of iron.
E) none of these
36) At the same time an astronaut on the moon sees a solar eclipse, observers on Earth see
A) a solar eclipse.
B) a lunar eclipse.
37) On some early automobiles both headlights went out when one bulb burned out. The headlights
must have been connected in
A) series.
B) haste.
C) parallel.
B) electric field.
C) energy.
37)
D) perpendicular.
38) You can touch a 100,000-volt Van de Graaff generator with little harm because although the
voltage is high, the relatively small amount of charge means there is a relatively small amount of
A) conduction.
36)
C) no eclipse at all.
38)
D) polarization.
39) Several paper clips dangle from the north pole of a magnet. The induced pole in the bottom of the
lowermost paper clip is a
39)
A) south pole.
B) north pole.
C) north or south pole - no difference really.
40) When a bar magnet is broken in two, each half is
40)
A) at most half as strong as the original magnet.
B) actually stronger than the original magnet.
C) as magnetic as the original magnet.
D) no longer magnetic.
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41) Pigeons navigate primarily by
41)
A) a keen sense of smell.
B) magnetic sensors in their heads.
C) ultra-high-pitched sounds.
D) a good memory.
E) none of these
42) When you view a distant rainbow, you view from each single water drop that contributes to the
bow
42)
A) a single color.
B) either low, middle, or high frequency colors in most cases.
C) all the colors of the rainbow.
43) A positive ion has more
43)
A) electrons than protons.
B) protons than electrons.
C) neutrons than protons.
D) protons than neutrons.
E) electrons than neutrons.
44) As the cranking arm of a motor turns faster and faster, net current in the motor windings
A) decreases.
B) increases.
44)
C) remains unchanged.
45) The primary purpose of a lightning rod is to
45)
A) attract lightning and guide it to the ground.
B) induce a charge opposite to that of charged clouds overhead.
C) cancel the electric field within the structure to which it is attached.
D) discharge the structure to which it is attached.
Figure 22-A
46) A balloon will stick to a wooden wall if the balloon is charged
A) negatively.
B) positively.
C) either positively or negatively.
D) None of the above choices are correct.
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46)
47) To say that an object is electrically polarized is to say
47)
A) it is to some degree magnetic.
B) its internal electric field is zero.
C) it is electrically charged.
D) it is only partially conducting.
E) its charges have been rearranged.
48) A wire moving at right angles to a magnetic field has NO induced voltage
48)
A) if it is made of copper.
B) if it is moving very fast.
C) if the wire is covered with insulation.
D) if it is moving slowly.
E) None of the above choices are correct.
49) Disregarding the effects of friction, a cyclist will coast farther when a lamp powered by a wheel
generator is
A) of high wattage.
B) of low wattage.
C) burned out.
49)
D) none of these
50) The output power of an ideal transformer is
50)
A) smaller than the input power.
B) equal to the input power.
C) greater than the input power.
D) may be any of these
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Answer Key
Testname: SAMPLE MID-TERM 4
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