Untitled Deck

Question 1

If the top circuit has an oscillation frequency of 1000 Hz, the frequency of the bottom circuit is:

Answer 1

1410 Hz

Question 2

Which current is changing more rapidly?

Answer 2

Current I2
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Question 3

Which of the following statements is FALSE?
A. A changing magnetic field can produce an electric current.
B. An emf is induced in a wire by moving the wire near a magnet.
C. An emf is induced in a wire by keeping a stationary magnet near the wire.
D. An emf is induced in a wire by changing the current in that wire.

Answer 3

An emf is induced in a wire by keeping a stationary magnet near the wire.

Question 4

An emf can be induced in a loop of wire by changing:
A. The magnetic field
B. The area of the loop in the field
C. The loop’s orientation with respect to the field
D. All of the above

Answer 4

All of the above

Question 5

A magnet, with its north pole pointed downwards, is falling directly above a wire loop. As the magnet approaches the wire loop (before it passes through the loop):
A. An induced current flows through the wire loop in a clockwise orientation (as seen from above).
B. An induced current flows through the wire loop in a counter-clockwise orientation (as seen from above).
C. No current flows through the wire loop.

Answer 5

An induced current flows through the wire loop in a counter-clockwise orientation (as seen from above).

Question 6

A long wire carries a current I as shown. What is the direction of the current in the circular conducting loop when I is decreasing?

Answer 6

The current flows clockwise

Question 7

What is the battery current immediately after the switch has been closed for a very long time?

Answer 7

2 A

Question 8

What is the battery current immediately after the switch has closed?

Answer 8

0 A

Question 9

An induced current flows clockwise as the metal bar is pushed to the right. The magnetic field points:

Answer 9

Into the screen

Question 10

A metal bar moves through a magnetic field. The induced charges on the bar are:

Answer 10

B.

Question 11

A square conductor moves through a uniform magnetic field. Which of the figures shows the correct charge distribution on the conductor?

Answer 11

Question 12

Immediately after the switch is closed, the lower loop exerts ____ on the upper loop.

Answer 12

an upward force

Question 13

A battery, a loop of wire, and a switch make a circuit below. A second loop of wire sits directly below the first. Immediately after the switch is reopened, what can we say about the current in the lower loop?

Answer 13

The loop has a counterclockwise current.

Question 14

A battery, a loop of wire, and a switch make a circuit below. A second loop of wire sits directly below the first. Long after the switch is closed, what can we say about the current in the lower loop?

Answer 14

The loop has no current.

Question 15

A battery, a loop of wire, and a switch make a circuit below. A second loop of wire sits directly below the first. Immediately after the switch is closed, what can we say about the current in the lower loop?

Answer 15

The loop has a clockwise current.

Question 16

A battery, a loop of wire, and a switch make a circuit below. A second loop of wire sits directly below the first. Just before the switch is closed, what can we say about the current in the lower loop?

Answer 16

The loop has no current.

Question 17

A magnetic field goes through a loop of wire, as below. If the magnitude of the magnetic field is constant, what can we say about the current in the loop?

Answer 17

The loop has no current

Question 18

A magnetic field goes through a loop of wire, as below. If the magnitude of the magnetic field is decreasing, what can we say about the current in the loop?

Answer 18

The loop has a clockwise current

Question 19

A magnetic field goes through a loop of wire, as below. If the magnitude of the magnetic field is increasing, what can we say about the current in the loop?

Answer 19

The loop has a counterclockwise current.

Question 20

The magnetic field is confined to the region inside the dashed lines; it is zero outside. The metal loop is being pulled out of the magnetic field. Which is true?

Answer 20

There is a clockwise induced current in the loop.

Question 21

The current in the straight wire is decreasing. Which is true?

A. There is a clockwise induced current in the loop.
B. There is a counterclockwise induced current in the loop.
C. There is no induced current in the loop.

Answer 21

There is a clockwise induced current in the loop.

Question 22

The bar magnet is pushed toward the center of a wire loop. Which is true?

A. There is a clockwise induced current in the loop.
B. There is a counterclockwise induced current in the loop.
C. There is no induced current in the loop.

Answer 22

There is no induced current in the loop.

Question 23

The bar magnet is pushed toward the center of a wire loop. Which is true?

A. There is a clockwise induced current in the loop.
B. There is a counterclockwise induced current in the loop.
C. There is no induced current in the loop.

Answer 23

There is a clockwise induced current in the loop.

Question 24

The induced emf around this loop is

Answer 24

0.02 V

Question 25

A loop of wire of area A is tipped at an angle θ to a uniform magnetic field B. The maximum flux occurs for an angle θ = 0°. What angle θ will give a flux that is ½ of this maximum value?

Answer 25

θ = 60°

Question 26

A metal bar moves through a magnetic field. The induced charges on the bar are

Answer 26

Question 27

The metal loop is rotating in a uniform magnetic field. Is the magnetic flux through the loop changing?

Answer 27

Yes

Question 28

The metal loop is being pulled through a uniform magnetic field. Is the magnetic flux through the loop changing?

Answer 28

No

Question 29

Which loop has the larger magnetic flux through it?

Answer 29

Loop B