21. In an ac circuit, resistance 5 ohm is connected with a capacitor having capacitive reactance 12 ohm. A supply of 260 V is connected to the circuit. Calculate the voltage across a capacitor.
A. 300 V
B. 200 V
C. 240 V
D. 100 V
21. Find the total voltage applied in a series RLC circuit when i = 3mA, VL = 30V, VC = 18V, and R = 1000 ohms.
A. 3.95V
B. 51V
C. 32.67V
D. 6.67V
22. In an RLC circuit, which of the following is always used as a vector reference?
A. Voltage
B. Resistance
C. Impedance
D. Current
23. In an RLC circuit, the power factor is always ____________
A. Positive
B. Negative
C. Depends on the circuit
D. Zero
24. In an RLC series phasor, we start drawing the phasor from which quantity?
A. Voltage
B. Resistance
C. Impedance
D. Current
25. What is the correct expression for the phase angle in an RLC series circuit?
A. φ = tan-1(XL-XC)/R
B. φ = tan-1 (XL+XC)/R
C. φ = tan(XL-XC)/R
D. φ = tan-1 (XL-XC)
26. When is tanφ positive?
A. When inductive reactance is less than the capacitive reactance
B. When inductive reactance is greater than the capacitive reactance
C. When inductive reactance is equal to capacitive reactance
D. When inductive reactance is zero
27. When is tanφ negative?
A. When inductive reactance is less than the capacitive reactance
B. When inductive reactance is greater than the capacitive reactance
C. When inductive reactance is equal to capacitive reactance
D. When inductive reactance is zero
28. Which of the following is not an ac waveform?
A. sinusoidal
B. square
C. constant
D. triangular
29. What is not a frequency for ac current?
A. 50 Hz
B. 55 Hz
C. 0Hz
D. 60 Hz
10. Which type of ac waveform is shown in the given figure?
A. sinusoidal
B. triangular
C. square
D. complex waveform