29. In a circuit element, the p.d. is higher than the applied voltage of the source. That will be

A. an a.c. circuit

B. a d.c. circuit

C. an a.c. or a d.c. circuit

D. neither a.c. ru:Yr d.c. circuit

30. A lamp consumes 25% of peak power in an a.c. circuit. What is the phase difference between the applied voltage and circuit current?

A. i/6

B. 7t/3

C.it/4

D.it/2

31. In R-L-C series a.c. circuit, the current

A. is always in phase with applied voltage

B. always lags behind the applied voltage

C. always leads the applied voltage

D. none of above

32. In an a.c. circuit, V and I are given y; V= 100 sin (100 t) volts I = 100 sin (100 t +71/3) mA The power dissipated in the circuit is

A. 2.5 W

B. 10 W

C. 5 W

D. 104 W

33. An a.c. source is in series with R and L. If the respective potential drops are 200 V and 150 V, the applied voltage is

A. 125 V

B. 350 V

C.200 V

D. 250 V

34. When 100 V d.c. is applied aross a solenoid, a current of IA flows in it. When 100 V a.c. is applied across it, the current drops to 0.5 A. If the frequency of a.c. is 50 Hz, the impedance and inductance of solenoid are

A. 100 S2; 0.25 fl

B. 200 ; 0.84 H

C.20052 ; 0.55 H

D. 10052 ; 0.84 H

35. In an R-L-C series circuit, the current through resistance and inductance has a phase difference of

A.702

B.n/3

C.it/4

D. 0?

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