Q. No.In an induction coil, the coefficient of mutual inductance is 4 H. If current of 5 A in the primary coil is cut off in second, the emf at the terminals of the secondary coil will be
1. 15 kV
2. 30 kV
3. 10 kV
4. 60 kV
Subtopic: Â Mutual Inductance |
 91%
Level 1: 80%+
Hints
Links
Two coils of self-inductance \(L_1\) and \(L_2\) are placed so close together that the effective flux in one coil is completely linked with the other. If \(M\) is the mutual inductance between them, then:
| 1. | \(M=L_1L_2\) | 2. | \(M=\dfrac{L_1}{L_2}\) |
| 3. | \(M=\sqrt{L_1L_2}\) | 4. | \(M=L^2_1L^2_2\) |
Subtopic: Â Mutual Inductance |
 90%
Level 1: 80%+
Please attempt this question first.
Hints
Please attempt this question first.
When the current in a certain coil changes at a rate of \(3~\text{A/s},\) an induced EMF of \(7~\text{mV}\) is observed in a nearby coil. What is the mutual inductance of this arrangement?
1. \(0.33~\text{mH}\)
2. \(1.66~\text{mH}\)
3. \(2.00~\text{mH}\)
4. \(2.33~\text{mH}\)
1. \(0.33~\text{mH}\)
2. \(1.66~\text{mH}\)
3. \(2.00~\text{mH}\)
4. \(2.33~\text{mH}\)
Subtopic: Â Mutual Inductance |
 88%
Level 1: 80%+
Please attempt this question first.
Hints
Please attempt this question first.
Two closed conducting loops have a mutual inductance of \(1~\text{H}.\) What is the average EMF induced in one loop if the current in the other loop changes by \(2~\text{A}\) in \(1~\text{s?}\)
1. \(1~\text{V}\)
2. \(2~\text{V}\)
3. \(3~\text{V}\)
4. \(4~\text{V}\)
1. \(1~\text{V}\)
2. \(2~\text{V}\)
3. \(3~\text{V}\)
4. \(4~\text{V}\)
Subtopic: Â Mutual Inductance |
 86%
Level 1: 80%+
Please attempt this question first.
Hints
Please attempt this question first.
Two coils of self-inductance \(2~\text{mH}\) and \(8~\text{mH}\) are placed so close together that the effective flux in one coil is completely linked with the other. The mutual inductance between these coils is:
1. \(16~\text{mH}\)
2. \(10~\text{mH}\)
3. \(6~\text{mH}\)
4. \(4~\text{mH}\)
1. \(16~\text{mH}\)
2. \(10~\text{mH}\)
3. \(6~\text{mH}\)
4. \(4~\text{mH}\)
Subtopic: Â Mutual Inductance |
 83%
Level 1: 80%+
Please attempt this question first.
Hints
Please attempt this question first.
Current varying at the rate \(4\) A/s in a coil generates an EMF of \(16\) mV in a nearby coil. The mutual inductance of the two coils is:
1. \(4.0\times 10^{-3}\) mH
2. \(4.0\times 10^{-3}\) H
3. \(2.5\times 10^{-2}\) H
4. \(2.5\times 10^{-2}\) mH
1. \(4.0\times 10^{-3}\) mH
2. \(4.0\times 10^{-3}\) H
3. \(2.5\times 10^{-2}\) H
4. \(2.5\times 10^{-2}\) mH
Subtopic: Â Mutual Inductance |
 83%
Level 1: 80%+
Please attempt this question first.
Hints
Please attempt this question first.
A small circular loop of radius \(r\) is placed inside a circular loop of radius \(R\) \(\left ( R\gg r \right ).\) The loops are coplanar and their centres coincide. The mutual inductance of the system is proportional to:
1. \(r/R \)
2. \(r^{2}/R \)
3. \(r/R^{2} \)
4. \(r^{2}/R^{2} \)
Subtopic: Â Mutual Inductance |
 80%
Level 1: 80%+
Hints
The mutual inductance between the two circuits can be determined by simply letting a current \(i\) flow through one circuit and finding the flux of the magnetic field through the second circuit: \(\phi_{2}=M_{12} i_{1}\), where \(M_{12}\) is the mutual inductance. Using this method, or otherwise determine the mutual inductance \((M)\) between a long straight wire, and a small coplanar loop of the area \(A\), located at a distance \(l\) from the wire. The value of \(M\) is:
| 1. | \( \dfrac{\mu_{0} l}{2 \pi}\) | 2. | \(\dfrac{\mu_{0} A}{2 \pi l}\) |
| 3. | \(\dfrac{\mu_{0} l^{3}}{4 \pi A}\) | 4. | \(\dfrac{\mu_{0} A^{2}}{2 \pi l^{3}}\) |
Subtopic: Â Mutual Inductance |
 80%
Level 1: 80%+
Hints
Given below are two statements:
| Assertion (A): | When two coils are wound on each other, the mutual induction between the coils is maximum. |
| Reason (R): | Mutual induction does not depend on the orientation of the coils. |
| 1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
| 3. | (A) is True but (R) is False. |
| 4. | Both (A) and (R) are False. |
Subtopic: Â Mutual Inductance |
 78%
Level 2: 60%+
Please attempt this question first.
Hints
Please attempt this question first.
Two circuits are placed close to each other: the first circuit \((A)\) carries a current \(i_A\) changing with time while the second circuit \((B)\) is kept closed with a resistance \(R_B\) in it.
The emf induced in the second circuit \((B)\) is proportional to:
1. \(i_A\)
2. \(\int i_A~dt\)
3. \(\dfrac{di_A}{dt}\)
4. \(\dfrac{d^2i_A}{dt^2}\)
The emf induced in the second circuit \((B)\) is proportional to:
1. \(i_A\)
2. \(\int i_A~dt\)
3. \(\dfrac{di_A}{dt}\)
4. \(\dfrac{d^2i_A}{dt^2}\)
Subtopic: Â Mutual Inductance |
 77%
Level 2: 60%+
Please attempt this question first.
Hints
Please attempt this question first.
© 2026 GoodEd Technologies Pvt. Ltd.