Q. No.Consider a long solenoid of length \(l\) and radius \(r.\) If \(n\) is the number of turns per unit length and \( \mu_0 \) is the permeability of free space, the inductance of the solenoid is:
1. \(2\mu_0 \pi n^2 r^2 l\)
2. \(\mu_0 \pi n^2 r^2 l\)
3. \(\mu_0 n^2 r^2 l\)
4. \((\mu_0/2 \pi)n^2r^2l\)
1. \(2\mu_0 \pi n^2 r^2 l\)
2. \(\mu_0 \pi n^2 r^2 l\)
3. \(\mu_0 n^2 r^2 l\)
4. \((\mu_0/2 \pi)n^2r^2l\)
Subtopic: Â Self - Inductance |
 60%
Level 2: 60%+
NEET - 2026
Please attempt this question first.
Hints
Please attempt this question first.
Two identical inductors are connected in two different configurations, \(P\) and \(Q,\) where a time-varying current \(I(t)\) is flowing, as shown in the figure. The induced EMF between points \(a\) and \(b\) for configuration \(P\) is \(E_P\) and that for configuration \(Q\) is \(E_Q.\) The ratio \(E_P/E_Q\) is:
(Neglect the effect of mutual inductance.)
(Neglect the effect of mutual inductance.)
| 1. | \(2\) | 2. | \(1/4\) |
| 3. | \(1/2\) | 4. | \(1\) |
Subtopic: Â Self - Inductance |
Level 4: Below 35%
NEET - 2026
Please attempt this question first.
Hints
Please attempt this question first.
Let us consider two solenoids \(A\) and \(B,\) made from the same magnetic material of relative permeability \(\mu_{r}\) and of equal area of cross-section. Length of \(A\) is twice that of \(B\) and the number of turns per unit length in \(A\) is half that of \(B.\) The ratio of self-inductances of the two solenoids, \(L_A:L_B\) is:
| 1. | \(1:2\) | 2. | \(2:1\) |
| 3. | \(8:1\) | 4. | \(1:8\) |
Subtopic: Â Self - Inductance |
 64%
Level 2: 60%+
NEET - 2024
Hints
The magnetic energy stored in an inductor of inductance \(4~\mu\text{H}\) carrying a current of \(2~\text{A}\) is:
1. \(8~\mu \text{J}\)
2. \(4~\mu \text{J}\)
3. \(4~\text{mJ}\)
4. \(8~\text{mJ}\)
1. \(8~\mu \text{J}\)
2. \(4~\mu \text{J}\)
3. \(4~\text{mJ}\)
4. \(8~\text{mJ}\)
Subtopic: Â Self - Inductance |
 79%
Level 2: 60%+
NEET - 2023
Hints
The current in an inductor of self-inductance \(4~\text{H}\) changes from \(4~ \text{A}\) to \(2~\text{A}\) in \(1~ \text s\). The emf induced in the coil is:
| 1. | \(-2~\text{V}\) | 2. | \(2~\text{V}\) |
| 3. | \(-4~\text{V}\) | 4. | \(8~\text{V}\) |
Subtopic: Â Self - Inductance |
 85%
Level 1: 80%+
NEET - 2022
Hints
An inductor coil of self-inductance \(10~\text{H}\) carries a current of \(1~\text{A}\). The magnetic field energy stored in the coil is:
| 1. | \(10~\text{J}\) | 2. | \(2.5~\text{J}\) |
| 3. | \(20~\text{J}\) | 4. | \(5~\text{J}\) |
Subtopic: Â Self - Inductance |
 86%
Level 1: 80%+
NEET - 2022
Hints
The magnetic potential energy stored in a certain inductor is \(25~\text{mJ},\) when the current in the inductor is \(60~\text{mA}.\) This inductor is of inductance:
| 1. | \(0.138~\text H\) | 2. | \(138.88~\text H\) |
| 3. | \(1.389~\text H\) | 4. | \(13.89~\text H\) |
Subtopic: Â Self - Inductance |
 72%
Level 2: 60%+
NEET - 2018
Hints
Links
A long solenoid has \(1000\) turns. When a current of \(4~\text{A}\) flows through it, the magnetic flux linked with each turn of the solenoid is \(4\times 10^{-3}~\text{Wb}\). The self-inductance of the solenoid is:
1. \(3~\text{H}\)
2. \(2~\text{H}\)
3. \(1~\text{H}\)
4. \(4~\text{H}\)
Subtopic: Â Self - Inductance |
 89%
Level 1: 80%+
NEET - 2016
Hints
Links
A coil of self-inductance \(L\) is connected in series with a bulb \(B\) and an AC source. The brightness of the bulb decreases when:
| 1. | number of turns in the coil is reduced. |
| 2. | a capacitance of reactance \(X_C = X_L\) is included in the same circuit. |
| 3. | an iron rod is inserted in the coil. |
| 4. | frequency of the AC source is decreased. |
Subtopic: Â Self - Inductance |
 68%
Level 2: 60%+
AIPMT - 2013
Hints
Links
The current \((I)\) in the inductance is varying with time \((t)\) according to the plot shown in the figure.
Which one of the following is the correct variation of voltage with time in the coil?
| 1. |  |
2. |  |
| 3. |  |
4. |  |
Subtopic: Â Self - Inductance |
 74%
Level 2: 60%+
AIPMT - 2012
Hints
Links
© 2026 GoodEd Technologies Pvt. Ltd.