## Physics MCQ on Alternating Current for NEET, JEE, Medical and Engineering Exam 2021

MCQ on Alternating Current: Alternating current can be defined as a current that changes its magnitude and polarity at regular interval of time. It can also be defined as an electrical current which repeatedly changes or reverses its direction opposite to that of Direct Current or DC which always flows in a single direction as shown below.

In this post we are providing you MCQ on Alternating Current, which will be beneficial for you in upcoming NEET, AIIMS, JEE, WBJEE, Medical and Engineering Exams. ## MCQ on Alternating Current

Q1. 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

(a) 5 V

Q2. If a current I given by I0sin(ωtπ2) flows across an AC circuit with potential E=E0sinωt, then what is the power consumption in the circuit?
a) P= E0Io/2
b) P= 2E0I0
c) P= E0I0/√2
d) P=0

(d) P=0

Q3. 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 cycle/sec

(b) 100/π cycle/sec

Q4. What is the r.m.s current value of an alternating current given by the equation of i=i1cosωt+i2sinωt?
a) 1/2(i1^2 + i2^2)^1/2
b) 1/2 ((i1^2 + i2^2)^1/2
c) 1/2 (i1+i2)
d) 1/2 (i1+i2)

(a) 1/2(i1^2 + i2^2)^1/2

Q5. What is the reciprocal of impedance?
b) Inductance
c) Reactance
d) Conductance

Q6.  What is the peak value of the voltage of an electric lamp connected to a 220 V, 50 Hz supply?
a) 311V
b) 320 V
c) 211 V
d) 210 V

(a) 311 V

Q7. 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

(d) The average value of a complete cycle is zero

Q8. 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

(c) 5×10-3 sec and 14.14 amp

Q9. What is the frequency of ac mains in India?
a) 120 Hz
b) 60 Hz
c) 50 Hz
d) 30 Hz

(c) 50Hz

Q10. If the peak current is given by Ipthen how much power is dissipated by a sinusoidal ac current which flows through resistor of resistance R?
a) Ip²RcosΘ
b) 4/πIp²R
c) 1/πIp²R
d) 1/2Ip²R

(d) 1/2Ip²R  