The GATE Grind

GATE Electrical Circuits and Machines: AC circuits and resonance – Previous Year Questions

13 GATE previous year questions on AC circuits and resonance (Electrical Circuits and Machines, Instrumentation Engineering) with answers and explanations, from every paper.

  1. GATE 2021 IN Q51 (2 marks, Numerical answer) – An air-cored coil of winding resistance 10 is in series with variable capacitor C x. A 10 V sinusoidal source has angular frequency 1000 rad/s. As…
  2. GATE 2022 IN Q33 (1 mark, Numerical answer) – For the bandpass-filter circuit shown, R 0=50\ , L 0=1 mH, and C 0=10 nF. Its Q factor is (two decimal places).
  3. GATE 2022 IN Q52 (2 marks, Numerical answer) – The load shown is driven by V 1=1000 V at 50 Hz. Given R 1=20\ , C 1=(1000/) μF, L 1=(20/) mH, and R 2=4\ , its power factor is (one decimal place).
  4. GATE 2022 IN Q60 (2 marks, Numerical answer) – A 1 kHz sine-wave generator with internal resistance 50 has open-circuit voltage 10 V peak-to-peak. A capacitor connected across its output reduces…
  5. GATE 2023 IN Q46 (2 marks, Numerical answer) – For the circuit shown, =100 rad/s, R 1=R 2=2.2 Ω, and L=7 mH. The capacitance making input admittance Y in purely real is mF (two decimal places).
  6. GATE 2023 IN Q65 (2 marks, Numerical answer) – The source V s=102(20000 t) V has internal resistance 50 Ω. The RMS current through R in the circuit shown is mA (one decimal place).
  7. GATE 2024 IN Q30 (1 mark, Numerical answer) – A circuit has voltage v(t)=95+200(120 t)+90(360 t-60) V and current i(t)=4(120 t-60)+1.5(240 t-75) A. Its average absorbed power is W (nearest…
  8. GATE 2024 IN Q31 (1 mark, Numerical answer) – The current drawn is i(t)=4+30 t-20 t+15(3t)-10(3t) A. Its RMS value is A (one decimal place).
  9. GATE 2025 IN Q25 (1 mark, Multiple choice) – Three admittances Y a=-j0.2 S, Y b=0.3 S, and Y c=j0.4 S are connected in parallel across V s=1045 V. Their currents are I a,I b,I c and the total…
  10. GATE 2025 IN Q62 (2 marks, Numerical answer) – A series RLC circuit resonates at 7500 rad/s for inductance L = 20 mH and resistance R = 10 Ω. The uncertainties in the measurement of L and R are 0.8…
  11. GATE 2025 IN Q65 (2 marks, Numerical answer) – For the circuit shown, the active power supplied by the source is W (rounded to one decimal place).
  12. GATE 2026 IN Q16 (1 mark, Multiple choice) – The RLC filter shown below acts as a .
  13. GATE 2026 IN Q33 (1 mark, Numerical answer) – In the series RL circuit shown, the current through the resistor lags the AC source voltage by 45. Let R=100\ and L=2\ H. The frequency of the source…