Ch 3 - L1 Electromagnetic Induction

The diagram below shows a bar magnet and three separate, copper loops. If the bar magnet is moved towards the loops, but not through them, in which loop will the smallest current be induced?

• Loop 2

• Loop 3

• Loop 1

• All loops will have same induced current

• 3 V

• 1.5 V

• 0.75 V

• 0.5 V

Which of the three wires in the figures below (if any) experiences an induced electromotive force?

• Wire b

• Wire c

• Wire a

• None of the answers are correct.

A straight wire of length 50 cm is moving in a magnetic field such that the direction of the current is perpendicular to the direction of the magnetic flux density. The following graph depicts the relation between the induced emf and the velocity of the wire. Given this information, the magnetic flux density is .........

• 1.5 T

• 0.4 T

• 0.01 T

• 1 T

A piece of wire whose ends are labelled A and B is moving perpendicularly to magnetic flux lines as shown in the following figure. so which of the following is correct?

• We do not have enough information to determine the answer

The wire is allowed to move in the space between the two poles of the magnet as shown in the following figure. If the magnet were to move in one of the following directions, which of these would cause the galvanometer needle to remain still?

• At any angle between the horizontal and the vertical directions

• Horizontally

• Vertically upwards

• • Vertically downwards

In the following figure, the current in the long wire produces a magnetic field in which a square coil is moving. Then, the induced current in the coil is ..........

• in the clockwise direction

• in the anticlockwise direction

• zero

• indeterminable given the information stated.

In the following figure, the current in the long wire produces a magnetic field in which a square coil is moving. Then, the induced current in the coil is ..........

• in the clockwise direction

• in the anticlockwise direction

• zero

• indeterminable given the information stated.

A metal rod of length 75 cm moves perpendicularly to a magnetic field of flux density 0.5 T with velocity 3.6m/s. The induced emf between its ends is

• 1.35 V

• 0.42 V

• 9.6 V

• 0.19 V

A conducting rod has a potential difference across it, as shown in the diagram. The rod moves through a uniform magnetic field. Which side of the field-containing region is the rod moving toward?

• Right side

• Top side

• Left side

• Bottom side