300+ TOP MCQs on Alternating Current and Answers

NEET  Physics is the very imporatant paper in the Medical Entrance EXAM. So these NEET Physics MCQs and Answers for all Concepts as per the new syllabus. Practice more on a regular basis with these NEET Physics objective questions on air pollution . NEET Physics Alternating Current Multiple Choice Questions

MCQs on Alternating Current :

1. What is the frequency of a 5μF capacitor that has a reactance of 1000 Ω?
(A) 200 cycle/sec
(B) 100/π cycle/sec
(C) 5000 cycles/sec
(D) 1000/π cycles/sec

Answer

Answer: (B) 100/π cycle/sec

2. What is the reciprocal of impedance?
(A) Admittance
(B) Inductance
(C) Reactance
(D) Conductance

Answer

Answer: (D) Conductance

3. What is the time taken by the alternating current of 50 Hz with an r.m.s value of 10 ampere to reach from zero to a maximum value and the peak value of current?
(A) 2 × 10^-2 sec and 14.24 amp
(B) 5 × 10^-3 sec and 8.07 amp
(C) 5 × 10^-3 sec and 14.14 amp
(D) 1 × 10^-2 sec and 7.07 amp

Answer

Answer: (C) 5×10^-3 sec and 14.14 amp

4. What is the voltage applied across the resonant circuit if the ac voltage across resistance R, inductance L and capacitance C is 5 V, 10 V and 10 V respectively?
(A) 5 V
(B) 10 V
(C) 20 V
(D) 25 V

Answer

Answer: (A) 5 V

5. Why can’t the DC ammeter measure an alternating current?
(A) AC cannot pass through a DC ammeter
(B) AC changes its direction
(C) AC is virtual
(D) The average value of a complete cycle is zero

Answer

Answer: (D) The average value of a complete cycle is zero

6. If the peak current is given by I_p, then how much power is dissipated by a sinusoidal ac current which flows through resistor of resistance R?

Answer

Answer: (D) (frac{1}{2} I_{p}^{2} R)

7. What is the frequency of ac mains in India?
(A) 120 Hz
(B) 60 Hz
(C) 50 Hz
(D) 30 Hz

Answer

Answer: (C) 50 Hz

8. If a current I given by I₀sin(ωt−(frac{pi}{2})) flows across an AC circuit with potential E=E₀sinωt, then what is the power consumption in the circuit?

Answer

Answer: (D) P = 0

9. What is the r.m.s current value of an alternating current given by the equation of i=i₁cosωt+i₂sinωt ?

Answer

Answer: (A) (frac{1}{sqrt{2}}left(i_{1}^{2}+i_{2}^{2}right)^{1 / 2})

10. What is the peak value of the voltage of an electric lamp connected to a 220 V, 50 Hz supply?
(A) 311 V
(B) 320 V
(C) 211 V
(D) 210 V

Answer

Answer: (A) 311 V