1. Q30.1
A small, circular ring of wire is inside a larger loop that is connected to a battery and a switch S. The small ring and the larger loop both lie in the same plane.
When the switch S is closed,
1. a clockwise current flows in the ring, caused by self-inductance
2. a counterclockwise current flows in the ring, caused by self-inductance
3. a clockwise current flows in the ring, caused by mutual inductance
4. a counterclockwise current flows in the ring, caused by mutual inductance

2. A30.1
A small, circular ring of wire is inside a larger loop that is connected to a battery and a switch S. The small ring and the larger loop both lie in the same plane.
When the switch S is closed,
1. a clockwise current flows in the ring, caused by self-inductance
2. a counterclockwise current flows in the ring, caused by self-inductance
3. a clockwise current flows in the ring, caused by mutual inductance
4. a counterclockwise current flows in the ring, caused by mutual inductance

3. Q30.2
A current i flows through an inductor L in the direction from point a toward point b. There is zero resistance in the wires of the inductor.
If the current is decreasing,
1. the potential increases from point a to point b
2. the potential drops from point a to point b
3. answer depends on the magnitude of di/dt compared to the magnitude of i
4. answer depends on the value of the inductance L
5. both 3. and 4. are correct

4. A30.2
A current i flows through an inductor L in the direction from point a toward point b. There is zero resistance in the wires of the inductor.
If the current is decreasing,
1. the potential increases from point a to point b
2. the potential drops from point a to point b
3. answer depends on the magnitude of di/dt compared to the magnitude of i
4. answer depends on the value of the inductance L
5. both 3. and 4. are correct

5. Q30.3
A steady current flows through an inductor. If the current is doubled while the inductance remains constant, the amount of energy stored in the inductor
1. increases by a factor of 21/2
2. increases by a factor of 2
3. increases by a factor of 4
4. increases by a factor that depends on the geometry of the inductor
5. none of the above

6. A30.3
A steady current flows through an inductor. If the current is doubled while the inductance remains constant, the amount of energy stored in the inductor
1. increases by a factor of 21/2
2. increases by a factor of 2
3. increases by a factor of 4
4. increases by a factor that depends on the geometry of the inductor
5. none of the above

7. Q30.4
An inductor (inductance L) and a resistor (resistance R) are connected to a source of emf as shown. When switch S is closed, a current begins to flow and grows until it reaches a final value.
The final value of the current
1. is directly proportional to both R and L
2. is directly proportional to R and inversely proportional to L
3. is inversely proportional to R and directly proportional to L
4. is inversely proportional to both R and L
5. is independent of L

8. A30.4
An inductor (inductance L) and a resistor (resistance R) are connected to a source of emf as shown. When switch S is closed, a current begins to flow and grows until it reaches a final value.
The final value of the current
1. is directly proportional to both R and L
2. is directly proportional to R and inversely proportional to L
3. is inversely proportional to R and directly proportional to L
4. is inversely proportional to both R and L
5. is independent of L

9. Q30.5
An inductor (inductance L) and a resistor (resistance R) are connected to a source of emf as shown. When switch S is closed, a current begins to flow and grows until it reaches a final value.
The time required for the current to reach half of its final value
1. is directly proportional to both R and L
2. is directly proportional to R and inversely proportional to L
3. is inversely proportional to R and directly proportional to L
4. is inversely proportional to both R and L
5. is independent of L

10. A30.5
An inductor (inductance L) and a resistor (resistance R) are connected to a source of emf as shown. When switch S is closed, a current begins to flow and grows until it reaches a final value.
The time required for the current to reach half of its final value
1. is directly proportional to both R and L
2. is directly proportional to R and inversely proportional to L
3. is inversely proportional to R and directly proportional to L
4. is inversely proportional to both R and L
5. is independent of L

11. Q30.6
An inductor (inductance L) and a capacitor (capacitance C) are connected as shown.
If the values of both L and C are doubled, what happens to the time required for the capacitor charge to oscillate through a complete cycle?
1. it becomes 4 times longer
2. is becomes twice as long
3. it is unchanged
4. it becomes 1/2 as long
5. it becomes 1/4 as long

12. A30.6
An inductor (inductance L) and a capacitor (capacitance C) are connected as shown.
If the values of both L and C are doubled, what happens to the time required for the capacitor charge to oscillate through a complete cycle?
1. it becomes 4 times longer
2. is becomes twice as long
3. it is unchanged
4. it becomes 1/2 as long
5. it becomes 1/4 as long