# Lesson Worksheet: Electromagnetic Induction Physics • 9th Grade

In this worksheet, we will practice describing the electric current induced in a wire that is placed in a changing magnetic field.

Q1:

The direction of the current induced in a conductor by a changing is such that the magnetic field created by the induced current the initial change in the magnetic field.

• Amagnetic field, amplifies
• Belectric field, amplifies
• Cmagnetic field, opposes
• Delectric field, opposes
• Emagnetic field, is perpendicular to

Q2:

The diagram shows a permanent magnet being moved through a loop of copper wire. This motion induces an electric current of 0.5 A in the wire. If the magnet is moved through the loop at half the speed, what will the current in the loop be?

• AGreater than 0.5 A
• B0.5 A
• CLess than 0.5 A
• D0 A

If the permanent magnet is changed for one that is twice as strong and moves through the loop at the original speed, what will the current in the loop be?

• ALess than 0.5 A
• B0.5 A
• C0 A
• DGreater than 0.5 A

Q3:

Diagram (a) shows a straight piece of copper wire moving along a rectangular path in a uniform magnetic field. Diagram (b) shows the potential difference across the piece of wire against time as it does so. Position in diagram (a) corresponds to the section marked in diagram (b). Which section of diagram (b) does position in diagram (a) correspond to?

• A
• B
• C
• D

Which position in diagram (a) does section in diagram (b) correspond to?

• APosition
• BPosition
• CPosition
• DPosition

Q4:

The diagram shows a permanent magnet being moved through a loop of copper wire. This motion induces an electric current in the wire. Which of the following correctly describes how the current within the wire can be increased?

• AThe current in the wire can be increased by increasing the radius of the wire loop.
• BThe current in the wire can be increased by increasing the thickness of the wire.
• CThe current in the wire can be increased by moving the magnet through the loop faster.
• DThe current in the wire can be increased by moving the wire at the same speed and in the same direction as the magnet.
• EThe current in the wire can be increased by reversing the direction of the motion of the magnet while keeping the wire in the same position.

Which of the following correctly describes how the current within the wire can be reversed?

• AThe current in the wire can be reversed by rotating the loop about its axis as the magnet passes through it.
• BThe current in the wire can be reversed by moving the magnet past the outside of the wire loop.
• CThe current in the wire can be reversed by reversing the direction of motion of the magnet while keeping the wire in the same position.
• DThe current in the wire can be reversed by moving the wire at the same speed and in the same direction as the magnet.
• EThe current in the wire can be reversed by moving the magnet through the loop faster.

What would be the effect of keeping the magnet still and moving the loop of wire toward it so that the magnet passes through it?

• AThe current in the wire would be zero.
• BThe same current would be induced in the wire.
• CThe current in the wire would be reversed.

What would be the effect of turning the magnet around so that the south pole of the magnet goes through the loop first?

• AThe current in the wire would be zero.
• BThe same current would be induced in the wire.
• CThe current would be reversed.

Q5:

Diagram (a) shows a straight piece of copper wire moving along a circular path in a uniform magnetic field. Diagram (b) shows the potential difference across the piece of wire against time as it does so. If point in diagram (a) corresponds to point in diagram (b), what point in diagram (a) does point in diagram (b) correspond to? • APosition
• BPosition
• CPosition
• DPosition

Q6:

Parts (a), (b), (c), and (d) of the diagram show a straight piece of copper wire moving through a magnetic field. The magnetic field is uniform and, in each part, the wire is moving at the same speed but in a different direction through the magnetic field. Which of (a), (b), (c), and (d) shows a motion of the wire that would lead to an electric potential difference being induced in the wire?

• A(b) and (d)
• B(a) and (c)
• C(b) and (c)
• D(a) and (b)
• E(a) and (d)

Q7:

Parts (a), (b), (c), and (d) in the diagram show a straight piece of copper wire moving through a magnetic field. The magnetic field is uniform, and in each part the wire is moving at the same speed, but in a different direction through the magnetic field. Which of (a), (b), (c), and (d) shows the motion of the wire that would lead to the greatest potential difference being induced in it? • A(a)
• B(d)
• C(b)
• D(c)

Q8:

Parts (a), (b), (c), and (d) in the diagram show a straight piece of copper wire moving through a magnetic field. The magnetic field is uniform, and in each part the wire is moving in a different direction through the magnetic field. Which of (a), (b), (c), and (d) show a motion of the wire that would lead to an electric potential difference being induced in it?

• A(c) and (d)
• B(a) and (d)
• C(a) and (b)
• D(a) and (c)
• E(b) and (d)

Q9:

Part (a) of the diagram shows a bar magnet moving at a speed toward a stationary solenoid. This induces an electric potential difference across the two ends of the solenoid. Part (b) of the diagram shows a stationary bar magnet, with a solenoid moving toward it at speed . How is the potential difference induced in the solenoid in part (b) different from that in part (a)? • AThe induced potential difference is zero as the magnet is not moving.
• BThe induced potential difference has the opposite sign.
• CThe induced potential difference is larger.
• DThe induced potential difference is smaller.
• EThe induced potential difference is the same.

Q10:

The diagram shows a bar magnet moving toward and then through a copper solenoid. This motion induces a potential difference across the two ends of the solenoid. Which of the following correctly describe ways that the potential difference across the ends of the solenoid could be increased?

1. The potential difference would be increased if the magnet was moved through the coil faster.
2. The potential difference would be increased if the number of turns of the coil was decreased.
3. The potential difference would be increased if the magnet was moved through the coil slower.
4. The potential difference would be increased if the number of turns of the coil was increased.
• Aa and d
• Ba and b
• Ca and c
• Db and d
• Ec and d