Module 9: Electromagnetic Induction and Inductance

Question 1

1. The induced current will be zero.
2. The current will flow clockwise and be increasing.
3. The current will flow counter-clockwise and be increasing.
4. The current will flow clockwise and be decreasing.
5. The current will flow counter-clockwise and be decreasing.

Answer 1

5. The current will flow counter-clockwise and be decreasing.

Question 2

1. from b to a.
2. from a to b.
3. There is no induced current through the resistor.

Answer 2

1. from b to a.

Question 3

1. is counterclockwise and caused by self-inductance.
2. is clockwise and caused by self-inductance.
3. is counterclockwise and caused by mutual inductance
4. is clockwise and caused by mutual inductance.

Answer 3

4. is clockwise and caused by mutual inductance.

Question 4

1. the potential is greater at point a than at point b.
2. The answer depends on the magnitude of di/dt compared to the magnitude of i.
3. The answer depends on the value of the inductance L.
4. both 2. and 3. are correct.
5. the potential is less at point a than at point b.

Answer 4

1. the potential is greater at point a than at point b.

Question 5

Comparing the mutual inductance M12 of coil 1 with respect to coil 2 with the mutual inductance M21 of coil 2 with respect to coil 1, it turns out that

1. M12 < or = M21.
2. M12 is always greater.
3. M21 is always greater
4. M12 = M21.
5. M12 > M21.

Answer 5

4. M12 = M21.

Question 6

1. loops 1 and 2
2. loop 3 only
3. loop 2 only
4. loops 2 and 3
5. loop 1 only

Answer 6

3. loop 2 only

Question 7

1. Both X and Y are north poles.
2. The polarities of the magnet cannot be determined from the information given.
3. X is a north pole, Y is a south pole.
4. X is a south pole, Y is a north pole.
5. Both X and Y are south poles.

Answer 7

4. X is a south pole, Y is a north pole.

Question 8

1. There is no induced current through the resistor.
2. from b to a.
3. from a to b.

Answer 8

3. from a to b