Electromagnetic Induction & AC · JEE Main previous year questions

2025 5 questions

1. Q312025 · 4 Apr 2025 · Shift 1

   An alternating current is represented by the equation, $i=100\sqrt{2}\sin (100\pi t)\text{ampere}$. The RMS value of current and the frequency of the given alternating current are

   1. A.$\frac{100}{\sqrt{2}}\mathrm{A},100\mathrm{Hz}$
   2. B.$50\sqrt{2}\mathrm{A},50\mathrm{Hz}$
   3. C.$100\sqrt{2}\mathrm{A},100\mathrm{Hz}$
   4. D.$100\mathrm{A},50\mathrm{Hz}$
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   Answer: D

2. Q472025 · 4 Apr 2025 · Shift 2· Numerical answer

   An inductor of self inductance $1\mathrm{H}$ is connected in series with a resistor of $100\pi \mathrm{ohm}$ and an ac supply of $100\pi \mathrm{volt}$, $50\mathrm{Hz}$ . Maximum current flowing in the circuit is ____ A.

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   Answer: 1

3. Q442025 · 3 Apr 2025 · Shift 2

   An electric bulb rated as $100\mathrm{W}-220\mathrm{V}$ is connected to an ac source of rms voltage $220\mathrm{V}$. The peak value of current through the bulb is :

   1. A.$0.32\mathrm{A}$
   2. B.$0.64\mathrm{A}$
   3. C.$0.45\mathrm{A}$
   4. D.$2.2\mathrm{A}$
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   Answer: B

4. Q442025 · 24 Jan 2025 · Shift 1

   An alternating current is given by $\mathrm{I}={\mathrm{I}}_{\mathrm{A}}\sin \omega t+{\mathrm{I}}_{\mathrm{B}}\cos \omega t$. The r.m.s current will be

   1. A.$\frac{\sqrt{{\mathrm{I}}_{\mathrm{A}}^2+{\mathrm{I}}_{\mathrm{B}}^2}}{2}$
   2. B.$\sqrt{\frac{{\mathrm{I}}_{\mathrm{A}}^2+{\mathrm{I}}_{\mathrm{B}}^2}{2}}$
   3. C.$\frac{|{\mathrm{I}}_{\mathrm{A}}+{\mathrm{I}}_{\mathrm{B}}|}{\sqrt{2}}$
   4. D.$\sqrt{{\mathrm{I}}_{\mathrm{A}}^2+{\mathrm{I}}_{\mathrm{B}}^2}$
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   Answer: B

5. Q472025 · 23 Jan 2025 · Shift 2· Numerical answer

   In a series LCR circuit, a resistor of $300\Omega$, a capacitor of $25\text{ nF}$ and an inductor of $100\text{ mH}$ are used. For maximum current in the circuit, the angular frequency of the ac source is _________ $\times 10^4{\text{ radians s}}^{-1}$

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   Answer: 2