An ideal inductor-resistor-battery circuit is switched on at \(t=0~\text{s}\). At time \(t\), the current is \(i=i_0\left(1-e^{\left(-\frac{t}{\tau}\right)}\right)\text{A}\), where \(i_0\) is the steady-state value. The time at which the current becomes \(0.5i_0\) is: [Given \(\text{ln}(2)= 0.693\)]
1. \(6.93 \times 10^3 ~\text{s}\)
2. \(6.93~\text{ms}\)
3. \(69.3~\text{s}\)
4. \(6.93~\text{s}\)

Subtopic:  LR circuit |
 60%
Level 2: 60%+
NEET - 2024
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A conducting circular loop of face area \(2.5 \times 10^{-3}~\text{m}^2\) is placed perpendicular to a magnetic field which varies as \(B=0.5~\text{sin}(100 \pi t)~\text{T}\). The magnitude of induced EMF at time \(t= 0~\text{s}\) is: 
1. \(0.125 \pi~ \text{mV}\) 2. \(125 \pi ~\text{mV}\)
3. \(125 \pi~\text{V}\) 4. \(12.5 \pi~\text{mV}\)
Subtopic:  Faraday's Law & Lenz Law |
 68%
Level 2: 60%+
NEET - 2024
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A rod of length \(L\) rotates with a small uniform angular velocity \(\omega\) about its perpendicular bisector. A uniform magnetic field \(B\) exists parallel to the axis of rotation. The potential difference between the centre of the rod and an end is:
1. \(\Large\frac{B\omega L^2}{8}\) 2. \(\Large\frac{B\omega L^2}{2}\)
3. \(\Large\frac{B\omega L^2}{4}\) 4. zero
Subtopic:  Motional emf |
Level 3: 35%-60%
NEET - 2024
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In the above diagram, a strong bar magnet is moving towards solenoid-\(2\) from solenoid-\(1\). The direction of induced current in solenoid-\(1\) and that in solenoid-\(2\), respectively, are through the directions:
1. \(BA\) and \(CD\) 2. \(AB\) and \(CD\)
3. \(BA\) and \(DC\) 4. \(AB\) and \(DC\)
Subtopic:  Faraday's Law & Lenz Law |
Level 3: 35%-60%
NEET - 2024
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An emf is generated by an ac generator having \(100\) turn coil, of loop area \(1\) m2. The coil rotates at a speed of one revolution per second and placed in a uniform magnetic field of \(0.05\) T perpendicular to the axis of rotation of the coil. The maximum value of emf is:
1. \(3.14\) V 2. \(31.4\) V
3. \(62.8\) V 4. \(6.28\) V
Subtopic:  Motional emf |
 75%
Level 2: 60%+
NEET - 2023
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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. \(8~\text{mJ}\)
Subtopic:  Self - Inductance |
 78%
Level 2: 60%+
NEET - 2023
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The magnetic flux linked to a circular coil of radius \(R\) is given by:
\(\phi=2t^3+4t^2+2t+5\) Wb.
What is the magnitude of the induced EMF in the coil at \(t=5\) s?

1. \(108\) V 2. \(197\) V
3. \(150\) V 4. \(192\) V
Subtopic:  Faraday's Law & Lenz Law |
 87%
Level 1: 80%+
NEET - 2022
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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:  Self - Inductance |
 85%
Level 1: 80%+
NEET - 2022
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The dimensions of mutual inductance \((M)\) are:
1. \(\left[M^2LT^{-2}A^{-2}\right]\) 2. \(\left[MLT^{-2}A^{2}\right]\)
3. \(\left[M^{2}L^{2}T^{-2}A^{2}\right]\) 4. \(\left[ML^{2}T^{-2}A^{-2}\right]\)
Subtopic:  Mutual Inductance |
 75%
Level 2: 60%+
NEET - 2022
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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:  Self - Inductance |
 85%
Level 1: 80%+
NEET - 2022
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