NEET Alternating Current PYQ practice sheet

15 previous-year NEET Physics questions from Alternating Current, newest papers first. Alternating Current carries 17 of the Physics questions in NEET 2020 to 2026, so this is a good place to test yourself after revising the chapter. Marking: +4 correct, −1 wrong.

1. 1.

   RE-NEET 2026

   An ac voltage $V = 220\sin(2\times10^{3}t)$ Volt is applied to a series LCR circuit. Then the current amplitude in this circuit is: (Given : $L = 10$ mH, $C = 25\ \mu$F, $R = 100\ \Omega$)

   • (A)
     $5.5\ \mathrm{A}$
   • (B)
     $2.2\ \mathrm{A}$
   • (C)
     $22.0\ \mathrm{A}$
   • (D)
     $11.0\ \mathrm{A}$
2. 2.

   NEET 2026

   An ac circuit contains a resistance of $1\ \text{k}\Omega$, a capacitor of $0.1\ \mu\text{F}$ and an inductor of 1 mH connected in series. The resonance frequency of the circuit is approximately:

   • (A)
     13.5 kHz
   • (B)
     15.9 kHz
   • (C)
     20.7 kHz
   • (D)
     10.1 kHz
3. 3.

   NEET 2026

   The peak value of an alternating current is 5 A and frequency is 60 Hz. How long will the current, starting from zero, take to reach the peak value?

   • (A)
     $\dfrac{1}{240}$ s
   • (B)
     $\dfrac{1}{60}$ s
   • (C)
     $\dfrac{1}{30}$ s
   • (D)
     $\dfrac{1}{120}$ s
4. 4.

   NEET 2024

   In an ideal transformer, the turns ratio is $\dfrac{N_p}{N_s}=\dfrac{1}{2}$. The ratio $V_s : V_p$ is equal to (the symbols carry their usual meaning):

   • (A)
     1 : 1
   • (B)
     1 : 4
   • (C)
     2 : 1
   • (D)
     1 : 2
5. 5.

   NEET 2024

   A $10\ \mu\text{F}$ capacitor is connected to a 210 V, 50 Hz source as shown in figure. The peak current in the circuit is nearly ($\pi=3.14$):

   • (A)
     0.35 A
   • (B)
     1.20 A
   • (C)
     0.58 A
   • (D)
     0.93 A
6. 6.

   NEET 2023

   In a series $LCR$ circuit, the inductance $L$ is $10\ \mathrm{mH}$, capacitance $C$ is $1\ \mu\mathrm{F}$ and resistance $R$ is $100\ \Omega$. The frequency at which resonance occurs is :

   • (A)
     $1.59\ \mathrm{kHz}$
   • (B)
     $15.9\ \mathrm{rad/s}$
   • (C)
     $15.9\ \mathrm{kHz}$
   • (D)
     $1.59\ \mathrm{rad/s}$
7. 7.

   NEET 2023

   A $12\ \mathrm{V}$, $60\ \mathrm{W}$ lamp is connected to the secondary of a step down transformer, whose primary is connected to ac mains of $220\ \mathrm{V}$. Assuming the transformer to be ideal, what is the current in the primary winding?

   • (A)
     $0.37\ \mathrm{A}$
   • (B)
     $0.27\ \mathrm{A}$
   • (C)
     $2.7\ \mathrm{A}$
   • (D)
     $3.7\ \mathrm{A}$
8. 8.

   NEET 2023

   The net impedance of circuit (as shown in figure) will be : A series circuit made of an inductor $\dfrac{50}{\pi}\ \mathrm{mH}$, a capacitor $\dfrac{10^{3}}{\pi}\ \mu\mathrm{F}$, a resistor $10\ \Omega$, connected to an ac source of $220\ \mathrm{V}$, $50\ \mathrm{Hz}$.

   • (A)
     $25\ \Omega$
   • (B)
     $10\sqrt2\ \Omega$
   • (C)
     $15\ \Omega$
   • (D)
     $5\sqrt5\ \Omega$
9. 9.

   NEET 2022

   The peak voltage of the ac source is equal to:

   • (A)
     $1/\sqrt2$ times the rms value of the ac source
   • (B)
     the value of voltage supplied to the circuit
   • (C)
     the rms value of the ac source
   • (D)
     $\sqrt2$ times the rms value of the ac source
10. 10.

    NEET 2022

    A series LCR circuit with inductance 10 H, capacitance 10 $\mu$F, resistance 50 $\Omega$ is connected to an ac source of voltage, $V=200\sin(100\,t)$ volt. If the resonant frequency of the LCR circuit is $\nu_0$ and the frequency of the ac source is $\nu$, then:

    • (A)
      $\nu=100$ Hz; $\nu_0=\dfrac{100}{\pi}$ Hz
    • (B)
      $\nu_0=\nu=50$ Hz
    • (C)
      $\nu_0=\nu=\dfrac{50}{\pi}$ Hz
    • (D)
      $\nu_0=\dfrac{50}{\pi}$ Hz, $\nu=50$ Hz
11. 11.

    NEET 2021

    An inductor of inductance $L$, a capacitor of capacitance $C$ and a resistor of resistance $R$ are connected in series to an ac source of potential difference $V$ volts as shown in figure. Potential difference across $L$, $C$ and $R$ is $40\ \mathrm{V}$, $10\ \mathrm{V}$ and $40\ \mathrm{V}$, respectively. The amplitude of current flowing through LCR series circuit is $10\sqrt{2}\ \mathrm{A}$. The impedance of the circuit is : Figure: a series loop containing the inductor, the capacitor and the resistor in that order, driven by an ac source $V$; the potential differences marked across them are $40\ \mathrm{V}$ (L), $10\ \mathrm{V}$ (C) and $40\ \mathrm{V}$ (R).

    • (A)
      $4\sqrt{2}\ \Omega$
    • (B)
      $4\ \Omega$
    • (C)
      $5\ \Omega$
    • (D)
      $\dfrac{5}{\sqrt{2}}\ \Omega$
12. 12.

    NEET 2021

    A series LCR circuit containing $5.0\ \mathrm{H}$ inductor, $80\ \mu\mathrm{F}$ capacitor and $40\ \Omega$ resistor is connected to $230\ \mathrm{V}$ variable frequency ac source. The angular frequencies of the source at which power transferred to the circuit is half the power at the resonant angular frequency are likely to be :

    • (A)
      $46\ \mathrm{rad/s}$ and $54\ \mathrm{rad/s}$
    • (B)
      $42\ \mathrm{rad/s}$ and $58\ \mathrm{rad/s}$
    • (C)
      $50\ \mathrm{rad/s}$ and $25\ \mathrm{rad/s}$
    • (D)
      $25\ \mathrm{rad/s}$ and $75\ \mathrm{rad/s}$
13. 13.

    NEET 2021

    A step down transformer connected to an ac mains supply of $220\ \mathrm{V}$ is made to operate at $11\ \mathrm{V}$, $44\ \mathrm{W}$ lamp. Ignoring power losses in the transformer, what is the current in the primary circuit ?

    • (A)
      $0.2\ \mathrm{A}$
    • (B)
      $4\ \mathrm{A}$
    • (C)
      $0.4\ \mathrm{A}$
    • (D)
      $2\ \mathrm{A}$
14. 14.

    NEET 2020

    A series LCR circuit is connected to an ac voltage source. When L is removed from the circuit, the phase difference between current and voltage is $\frac{\pi}{3}$. If instead C is removed from the circuit, the phase difference is again $\frac{\pi}{3}$ between current and voltage. The power factor of the circuit is :

    • (A)
      zero
    • (B)
      0.5
    • (C)
      1.0
    • (D)
      -1.0
15. 15.

    NEET 2020

    A $40\ \mu$F capacitor is connected to a $200$ V, $50$ Hz ac supply. The rms value of the current in the circuit is, nearly :

    • (A)
      1.7 A
    • (B)
      2.05 A
    • (C)
      2.5 A
    • (D)
      25.1 A