Series and Parallel Resonance MCQ

21. In an RLC series circuit with constant voltage source but of frequency varying from zero to infinity, the circuit is said to be in electrical resonance when

1. magnitude of X_L > X_C and Z ≠ R
2. magnitude of X_L = X_C and Z ≠ R
3. magnitude of X_L = X_C and Z = R
4. magnitude of X_L < X_C and Z ≠ R

22. Q- meter is based on characteristics of

1. Parallel resonant circuit
2. Series parallel circuit
3. Series parallel circuit
4. Inductive reactance circuit

23. Q-factor is defined as the ratio of

1. Resistance/inductance of reactive element
2. Resistance/capacitance of reactive element
3. Resistance to reactance of reactive element
4. Resistance to susceptance of reactive element

24. A choke coil having resistance R ohm and of inductance henry is shunted by a capacitor of C farads. The dynamic impedance of the resonant circuit would be

1. R/LC
2. C/RL
3. L/RC
4. 1/RLC

25. Magnitude of current at resonance in R-L-C circuit

1. Depends upon magnitude of R
2. Depending upon magnitude of L
3. Depends upon magnitude of C
4. Depends upon magnitude of R, L and C

26. If a parallel resonant circuit is shunted by resistance, then

1. The circuit impedance is increased
2. Q of the circuit is increased
3. The gain of the circuit is increased
4. The circuit impedance is decreased

27. The Exponential damping coefficient alpha is given by

1. 1/2 RC for a parallel RLC circuit
2. 2RC for a series RLC circuit
3. R/2L for a parallel RLC circuit
4. 2L/R for a series RLC circuit

28. A series RLC circuit is in resonance at 100Hz. If capacitance is made four times, the resonant frequency will be

1. 50 Hz
2. 100 Hz
3. 200 Hz 
4. 400 Hz

29. If Q of a coil is increased, its power factor will

1. Decrease
2. Increase
3. Remains same
4. None of these

30. A resonance curve for a series circuit is a plot of frequency versus

1. current
2. voltage
3. impedance
4. reactance