 # AC Circuit objective questions (mcq) and answers

11.  When an alternating current passes through an ohmic resistance the electrical power converted into heat is

A. Apparent power

B. True power

C. Reactive power

D. None of the above

B. True power

12.  In an AC circuit ( sine wave ) with R and L in series

A. Voltage across R and L 180o out of face

B. The voltage across R lags the voltage across L by 90o

C. The voltage across R leads the voltage across L by 90o

D. Voltage across R and L are in phase

B. The voltage across R lags the voltage across L by 90o

13.  In AC circuit the power curve is a sine wave having

A. Double the frequency of voltage

B. Same frequency as that of voltage

C. Half the frequency of the voltage

D. Three times the frequency of the voltage

A. Double the frequency of voltage

14.  A parallel AC circuit in resonance will

A. Have current in each section equal to the line current

B. Have a high-voltage developed across each inductive and capacitive section

C. Act like a resister of low value

D. Have a high impedance

D. Have a high impedance

15.  The square waveform of current has following relation between r.m.s. value and average value

A. r.m.s. value is equal to average value

B. r.m.s. value of current is greater than average value

C. r.m.s. value of current is less than average value

D. None of the above