Electromagnetic Induction

A straight wire, 0.5 m long, is moved straight up at a speed of 20 m/s through a 0.4T magnetic field pointed in the horizontal direction.

What EMF is induced in the wire?

• 8 volt

• 4 volt

• 2 volt

• 0 volt

A straight wire, 0.5 m long, is moved straight up at a speed of 20 m/s through a 0.4-T

magnetic field pointed in the horizontal direction.

The wire is part of a circuit of total resistance of 6.0 Ohms' .

What is the current in the circuit?

• 0.3 A

• 0.4 A

• 0.7 A

• 0 A

A straight wire, 2500 cm long, is mounted on an airplane flying at 125 m/s. The wire moves in a perpendicular direction through Earth’s magnetic field (B = 5.0x10^-5 T).

What EMF is induced in the wire?

• 0.16 volt

• 0.10 volt

• 0.5 volt

• 0.2 volt

A permanent horseshoe magnet is mounted so that the magnetic field lines are vertical. If a student passes a straight wire between the poles and pulls it toward herself, the current flow through the wire is from right to left. Which is the north pole of the magnet?

• The north pole is to the right

• The north pole is to the left

• The north pole is at the Top

• The north pole is at the bottom

A copper wire of insignificant resistance is placed in

the center of an air gap between two magnetic

poles, as shown in Figure . The field is

confined to the gap and has a strength of 1.9 T.

Determine the force on the wire (direction

and magnitude) when the switch is

closed.

• 0.62 N , UP

• 0.62 N , Down

• 0.31 N, Up

• 0.31 N, Down

A wire is moved horizontally between the poles of

a magnet, as shown in Figure . What is the

direction of the induced current?

• Maximum current is induced because the

  direction of the velocity is perpendicular to

  the magnetic field.

• No current is induced because the

  direction of the velocity is perpendicular perpendicular to

  the magnetic field.

• No current is induced because the direction of the velocity is parallel to

  the magnetic field.

• Maximum current is induced because the

  direction of the velocity is parallel to

  the magnetic field.

A segment of a wire loop is moving

downward through the poles of a magnet,

as shown in Figure .

What is the direction of the induced current?

• The current direction is inward-to the page to

  the Right along the path of the wire.

• The current direction is out-of-page to

  the left along the path of the wire.

• The current direction is upward -of-page perpendicular the path of the wire.

• The current direction is inward to the page perpendicular the path of the wire.

At what speed would a 20 cm length of

wire have to move across a 2.5 T magnetic

field to induce an EMF of 10 V?

• 20 m/s

• 10 m/s

• 5 m/s

• 2.5 m/s

You wish to generate an EMF of 4.5 V by

moving a wire at 4.0 m/s through a 50 mT

magnetic field. How long must the wire be,

and what should be the angle between the

field and direction of motion to use the

shortest wire?

• 10 m

• 50 m

• 12 m

• 23 m

A 40.0-cm wire is moved perpendicularly

through a magnetic field of 0.32 T with a

velocity of 1.3 m/s. If this wire is connected

into a circuit of 10.0 Ohm's resistance, what is

the current?

• 10 mA

• 17 A

• 17 mA

• 10 A