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a c fundamentals circuits and circuit theory MCQs

Practise focused a c fundamentals circuits and circuit theory questions with marked answers for exam preparation and subject revision.

a c fundamentals circuits and circuit theory Mcqs
1. The peak value of a sine wave is 200 V. Its average value is___________?
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A. 127.4 V

B. 200V

C. 141.4 V

D. 282.8 V

2. In a series resonant circuit, the impedance of the circuit is___________?
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A. maximum

B. minimum

C. none of the above

D. zero

3. In a highly capacitive circuit the__________?
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A. reactive power is more than the apparent power

B. reactive power is more than the actual power

C. actual power is more than its reactive power

D. apparent power is equal to the actual power

4. The r.m.s. value of a sinusoidal A.C. current is equal to its value at an angle of_______degrees?
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A. 30

B. 90

C. 60

D. 45
5. In a circuit containing R, L and C, power loss can take place in____________?
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A. L only

B. C only

C. all above

D. R only
6. Two waves of the same frequency have opposite phase when the phase angle between them is_________?
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A. 90

B. 360

C. 0

D. 180
7. Power factor of an inductive circuit is usually improved by connecting capacitor to it in____________?
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A. series

B. parallel

C. none of the above

D. either A. or (b)

8. The power consumed in a circuit element will be least when the phase difference between the current and voltage is__________?
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A. 0

B. 60

C. 90

D. 180?

9. Form factor for a sine wave is________?
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A. 1.414

B. 1.11

C. 0.637

D. 0.707

10. For the same peak value which of the following wave will have the highest r.m.s. value?
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A. sine wave

B. triangular wave

C. half wave rectified sine wave

D. square wave
11. For a sine wave with peak value Emax _______ 8.30. the average value is?
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A. 0.434 EWc

B. lAUEmax

C. 0.636 Emax

D. 0.707 Emax

12. The form factor is the ratio of_______?
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A. peak value to r.m.s. value

B. none of the above

C. r.m.s. value to average value

D. average value to r.m.s. value

13. The double energy transient occur in the____________?
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A. R-L-C circuit

B. R-C circuit

C. purely inductive circuit

D. R-L circuit

14. For the same peak value, which of the following wave has the least mean value ?
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A. half wave rectified sine wave

B. sine wave

C. square wave

D. triangular wave

15. Power factor of an electrical circuit is equal to____________?
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A. all of these

B. cosine of phase angle difference be-tween current and voltage

C. ratio of useful current to total current Iw/I

D. R/Z

E. kW/kVA

16. Power factor of the following circuit will be zero__________?
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A. resistance

B. inductance

C. capacitance

D. both B. and C.
17. All the rules and laws of D.C. circuit also apply to A.C. circuit containing_____________?
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A. all above

B. capacitance only

C. resistance only

D. inductance only

18. Pure inductive circuit____________?
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A. does not take power at all from a line

B. none of the above

C. takes power from the line during some part of the cycle and then returns back to it during other part of the cycle

D. consumes some power on average

19. In a pure inductive circuit___________?
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A. the current lags behind the voltage by 90

B. the current is in phase with the voltage

C. the current can lead or lag by 90

D. the current leads the voltage by 90

20. For a sine wave with peak value Imax the r.m.s. value is_______?
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A. 0.9

B. 0.707

C. 0.5 Imax

D. 1.414 Lmax