Test Bank For Physics of Everyday Phenomena 9th edition By W Thomas

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Test Bank For Physics of Everyday Phenomena 9th edition By W Thomas

Chapter 14   Magnets and Electromagnetism

 

1) Electrons flow around a circular wire loop in a horizontal plane, in a direction that is clockwise when viewed from above. This causes a magnetic field. Inside the loop, the direction of this field is

1. A) toward the center of the loop.
2. B) radially outward from the center of the loop.
3. C) up, toward the viewer.
4. D) down, away from the viewer.

 

2) A horizontally moving positive sodium ion enters a magnetic field that points up. The magnetic force pushes the charge out of its original path.

 

 

When viewed as shown on this page, what direction will the magnetic force point?

1. A) Into the page
2. B) Out of the page
3. C) There is not enough information to answer

 

3) Which of these will always produce a magnetic field?

1. A) A positive charge at rest
2. B) Another magnetic field
3. C) A moving charge
4. D) A negative charge at rest

 

4) Imagine that this classroom contains a constant magnetic field that points from the front to the back. In front of you a negative charge is slowly moving horizontally to your left. As you watch, the magnetic force on the charge

1. A) deflects the charge away from you.
2. B) deflects the charge into a clockwise directed vertical circle.
3. C) deflects the charge toward you.
4. D) has no effect on the charge.
5. E) deflects the charge into a counterclockwise vertical circle.

 

 

5) When a current is induced by a changing magnetic field B1, the current always produces a second magnetic field B2 such that

1. A) B1and B2completely cancel each other out.
2. B) B1and B2combine to give a stronger magnetic field than B1
3. C) B1and B2combine to give a weaker magnetic field than B1
4. D) It is not possible to tell whether the combined field is stronger or weaker than B1without knowing how B1is changing

 

6) A permanent magnet is produced when

1. A) magnetic fields of large groups of individual atoms are permanently aligned.
2. B) electrons become stuck and cease to move.
3. C) electrical fields exchange electrons with the magnetic fields.
4. D) current is made to circulate in a clockwise direction in a loop of wire.

 

7) A positive charge is released from rest near a bar magnet. The magnetic force on the charge

1. A) there is no magnetic force on the charge.
2. B) either pole of the magnet will repel the positive charge.
3. C) can only be attracted toward the S pole of the magnet.
4. D) can only be attracted toward the N pole of the magnet.

 

8) A bar magnet and an electrically polarized object are placed next to each other on a table. What happens?

1. A) The positive part of the object turns toward the north pole of the magnet
2. B) The positive part of the object turns toward the south pole of the magnet
3. C) The object and magnet accelerate toward each other until they touch and then they repel
4. D) Nothing happens

 

9) A current flowing through a long, straight wire causes a magnetic field that points

1. A) along the wire.
2. B) along concentric circles around the wire.
3. C) radially inward toward the wire.
4. D) radially outward from the wire.

10) A little magnetic compass has a needle whose tips are clearly labeled N and S. The compass is placed next to a single circular loop of wire lying flat on a wooden table. The

current in the loop is clockwise. What happens?

1. A) The S tip of the needle is attracted toward the loop
2. B) The N tip of the needle is attracted toward the loop
3. C) The needle orients itself with the N tip pointing in the direction of the current in the segment of the loop closest to the needle
4. D) The needle orients itself with the S tip pointing in the direction of the current in the segment of the loop closest to the needle
5. E) None of these choices are correct

 

 

 

11) A magnetic compass points towards the north geographic pole of the Earth because

1. A) all magnetic poles, north or south, point that way due to the spin of the Earth.
2. B) the static electricity in the atmosphere causes the alignment of the compass.
3. C) there is a north magnetic pole near the north geographic pole.
4. D) there is a south magnetic pole near the north geographic pole.

 

12) Two identical coils of wire are placed on a single horizontal wooden broom handle. The coils are separated by a few centimeters. We now run identical currents in the same direction through each coil. The coils experience

1. A) no forces because the currents are identical.
2. B) a repulsive magnetic force.
3. C) an attractive magnetic force.
4. D) an attractive electrostatic force because one coil is negatively charged and the other positively charged.
5. E) a repulsive electrostatic force because both coils are identically charged.

 

13) Which of the following cannot induce a voltage in a loop of wire?

1. A) Moving a magnet near the loop
2. B) Moving the loop near a magnet
3. C) Expanding or contracting the loop in a region where there is no magnetic field
4. D) Changing the current in a nearby loop

 

14) An ideal transformer is used to either increase or decrease the voltage in an AC circuit. When the output voltage is greater than the input voltage of a transformer then

1. A) the power output depends on the ratio of turns in the primary and secondary.
2. B) the power output is the same as the power input.
3. C) the power output is larger than the power input.
4. D) the power output is smaller than the power input.

15) A positively charged ping pong ball is sitting stationary on the floor in the center of a room. There is also a constant, uniform magnetic field in the room that points toward the ceiling. If I now start the ball rolling toward the back of the room, the resultant motion of the ball, as observed from the ceiling, will be

1. A) a diagonal straight line toward the left back corner of the room.
2. B) a diagonal straight line toward the right back corner of the room.
3. C) a horizontal, clockwise circle.
4. D) a horizontal, counterclockwise circle.

E) a straight line in the original direction of motion