Practice Alternating Current And Voltage Multiple Choice Questions with Answers Quiz-3

Q.1.

If the peak of a sine wave isV, the peak-to-peak value is

6.5 V
13 V
26 V
none of the above

Q.2.

A phasor represents

the magnitude and a quantity direction
the width of a quantity
the phase angle
the magnitude of a quantity

Q.3.

To produce anHz sine wave, a four-pole generator must be operated at

200 rps
400 rps
800 rps
1,600 rps

Q.4.

A sawtooth wave has a period ofms. Its frequency is

10 Hz
50 Hz
100 Hz
1,000 Hz

Q.5.

The average half-cycle value of a sine wave with aV peak is

25.48 V
6.37 V
14.14 V
50.96 V

Q.6.

A sinusoidal current has an rms value ofmA. The peak-to-peak value is

45.12 mA
16 mA
39.6 mA
22.6 mA

Q.7.

The average half-cycle value of a sine wave with aV peak is

25.48 V
6.37 V
14.14 V
50.96 V

Q.8.

One sine wave has a positive-going zero crossing atand another sine wave has a positive-going zero crossing at 55°. The phase angle between the two waveforms is

0°
45°
40°
none of the above

Q.9.

One sine wave has a positive-going zero crossing atand another sine wave has a positive-going zero crossing at 55°. The phase angle between the two waveforms is

0°
45°
40°
none of the above

Q.10.

AC stands for

Air-conditioner
Direct Current
Alternating Current
Alternating Voltage

Q.11.

Power Factor (Cos θ) =_________?

R/Z
The Cosine of angle between rms Current and rms voltage
Both A and B
Neither A nor B

Q.12.

A pure capacitor is connected to an AC power supply. In this circuit, the current

leads the voltage by 90°.
lags the voltage by 90°.
is in phase with the voltage.
none of the given answers

Q.13.

What words are missing from the following statement? The impedance of a series RCL circuit at resonance will be _______ and equal to the circuit _______ .

Minimum and resistance.
Maximum and resistance.
Minimum and reactance.
Maximum and reactance

Q.14.

Battery is

AC source
DC source
none of the above
all of the above

Q.15.

In a circuit containing resistance only, the voltage and current are ____________________ with oneanother.

together
anti phase
in phase
full rotation

Q.16.

The power factor is the ratio of __________________ power to _________________ power.

true and apparent
true and real
positive and negative
factor and real

Q.17.

The current in an inductive circuit _____.

is faster than the voltage
is the same as the voltage
lags the voltage
counteracts the voltage

Q.18.

When frequency decreases, capacitive reactance _____.

increases
decreases
remains the same
may increase or decrease

Q.19.

Which of the following is true of the current in a capacitive circuit?

It leads the voltage.
It lags the voltage.
It is the same as the voltage.
It counteracts the voltage.

Q.20.

Inductive reactance increases as the _____.

frequency increases
frequency decreases
impedance increases
impedance decreases

Q.21.

The power factor can be defined as the ratio of true power to _____.

apparent power
total resistance
total current
reactive power

Q.22.

What does RC stand for?

Remote Control
Radio Control
Resistor Capacitor
Rotary Club

Q.23.

The unit of inductive reactance is :

Ohm
Ampere
Farad
Henry

Q.24.

What does RMS means?

Really Monday Stinks
Root Minus Square
Root Mean Square
Root Minus Subtraction

Q.25.

An A.C source is connected to a resistive circuit. Which of the following is true ?

Current leads the voltage and both are in same phase
Current lags behind the voltage and both are in same phase
Current and voltage are in same phase
Any of the above may be true depending upon the value of resistance

Q.26.

A pure capacitor of capacitance C is connected to an a.c. supply of peak voltage VWhich pair of expressions below are for the voltage and current in the circuit?

V=V0 sin⁡ (ωt+π2)V=V_0\ \sin\ \left(\omega t+\frac{\pi}{2}\right)V=V0 sin (ωt+2π) I=I0 sin⁡ωtI=I_0\ \sin\omega tI=I0 sinωt
V=V0 sin⁡ (ωt+π2)V=V_0\ \sin\ \left(\omega t+\frac{\pi}{2}\right)V=V0 sin (ωt+2π) I=I0 cos⁡ ωtI=I_0\ \cos\ \omega tI=I0 cos ωt
V=V0 sin⁡ ωtV=V_0\ \sin\ \omega tV=V0 sin ωt I=I0cos⁡ ωtI=I_0\cos\ \omega tI=I0cos ωt
V=V0 sin⁡ ωtV=V_0\ \sin\ \omega tV=V0 sin ωt I=I0 sin⁡ ωtI=I_0\ \sin\ \omega tI=I0 sin ωt

Q.27.

A pure inductor is connected to an a.c. source of frequencyHz and the r.m.s. value of the voltage isV. If the peak value of the current flowing through the inductor isA, what is the inductance of the inductor?

1.6 mH
1.9 mH
30 mH
39 mH

Q.28.

A pure inductor of inductanceH is connected to an a.c.s source of frequencyHz. If the r.m.s. value of the voltage isV, what is the maximum instantaneous output power?

1.3 ×10−3W\times10^{-3}W×10−3W
1.5 ×10−2W\times10^{-2}W×10−2W
0 W
1.5 W

Q.29.

A pure capacitor is connected to an a.c. supply of frequencyHz and r.m.s. voltage 6.0 V. If the r.m.s. value of the current in the circuit ismA, what is the capacitance of the capacitor?

13 μ\muμ F
14 \muμ F
15 \muμ F
16 \muμ F

Q.30.

An electrical element X when connected to an alternating voltage source has current through it leading the voltage by 2radian. Identify X

Capacitor
Resistor
Inductor
Series LR circuit

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