# Circuit Theory Quiz | Circuit Theory Multiple Choice Questions and Answers

Questions
1 For a frequency of 200 Hz, the time period will be
A 0.005 s
B 0.5 s
C 0.0005 s
D 0.05 s

2 For a sine wave with peak value Emax______8.30. the average value is
A lAUEmax
B 0.636 Emax
C 0.707 Emax
D 0.434 EWc

3 Form factor for a sine wave is
A 1.414
B 0.707
C 1.11
D 0.637

4 Form Factor is the ratio of
A r.m.s. value/average value
B r.m.s. value/peak value
C average value/r.m.s. value
D average value/peak value

5 For a sine wave with peak value Imax the r.m.s. value is
A 0.5 Imax
B 0.707
C 0.9
D 1.414 Lmax

6 For the same peak value, which of the following wave has the least mean value ?
A half wave rectified sine wave
B triangular wave
C sine wave
D square wave

Answer: half wave rectified sine wave
7 For the same peak value which of the following wave will ‘have the highest r.m.s. value ?
A square wave
B half wave rectified sine wave
C triangular wave
D sine wave

8 The r.m.s. value and mean value is the same in the case of
A triangular wave
B sine wave
C square wave
D half wave rectified sine wave

9 The power consumed in a circuit element will be least when the phase difference between the current and voltage is
A 180″
B 90°
C 60°
D none of the above

10 Two waves of the same frequency have opposite phase when the phase angle between them is
A 360°
B 180°
C 90°
D

11 The voltage of domestic supply is 220V. This figure represents
A mean value
B r.m.s. value
C peak value
D average value

12 If two sine waves of the same frequency have a phase difference of JT radians, then
A both will reach their minimum values at the same instant
B both will reach their maximum values at the same instant
C when one wave reaches its maxi¬mum value, the other will reach its minimum value
D none of the above

Answer: when one wave reaches its maxi¬mum value, the other will reach its minimum value
13 The peak value of a sine wave is 200 V. Its average value is
A 127.4 V
B 141.4 V
C 282.8 V
D 200V

14 If two sinusoids of the same frequency but of different amplitudes and phase angles are subtracted, the resultant is
A a sinusoid of the same frequency
B a sinusoid of half the original frequency
C a sinusoid of double the frequency
D not a sinusoid

Answer: a sinusoid of the same frequency
15 A heater is rated as 230 V, 10 kW, A.C. The value 230 V refers to
A average voltage
B r.m.s. voltage
C peak voltage
D none of the above

16 The period of a sine wave is _____ seconds. Its frequency is
A 20 Hz
B 30 Hz
C 40 Hz
D 50 Hz

17 The form factor is the ratio of
A peak value to r.m.s. value
B r.m.s. value to average value
C average value to r.m.s. value
D none of the above

Answer: r.m.s. value to average value
18 The period of a wave is
A the same as frequency
B time required to complete one cycle
C expressed in amperes
D none of the above

Answer: time required to complete one cycle
19 The reactance offered by a capacitor to alternating current of frequency 50 Hz is 20 Q. If frequency is increased to 100 Hz, reactance becomes_____ohms.
A 2.5
B 5
C 10
D 15