21. Two capacitors of capacitance 9 µF and 18 µF in series will have a total capacitance of:
A. 27 µF
B. 6 pF
C. 162 µF
D. 180 µF
22. In a series RLC circuit:
A. Increasing the frequency decreases the resistance
B. Both XL and Xc change as frequency charms
C. Increasing the frequency increases the resistance
D. Impedance will always decrease
23. A series RLC circuit has a ________ power factor at its half-power points
A. Unity
B. Leading
C. Lagging
D. Either B or C
24. Kirchhoff’s laws (KCL and KVL) are applicable to:
A. DC circuits
B. AC circuits
C. Passive networks alone
D. DC as well AC circuits
25. A tank circuit is a:
A. Parallel LC Circuit
B. Series LC circuit
C. A resonant circuit
D. A non-resonant circuit
26. A capacitive load always has a______ power factor.
A. Leading
B. Lagging
C. Zero
D. Unity
27. What is the temperature coefficient of the resistance Eureka?
A. Infinity
B. Negative
C. Almost Zero
D. Positive
28. As applied to a series RLC circuit, bandwidth means
A. The frequency range for maximum power transfer
B. The difference between the highest and lowest frequencies of the oscillator
C. The frequency at which XL = Xc
D. The separation of the half-power points
29. Which is considered as the effect of a dielectric material?
A. Increasing capacitance
B. Decreasing capacitance
C. Reducing the working voltage
D. Increasing the distance between the plates
30. The open-circuit voltage at the terminal of load RL is 60V. Under the condition of maximum power transfer, the load voltage will be:
A. 60 V
B. 15 V
C. 30V
D. 20 V
31. If a capacitor is rated for 200V dc, what is its effective ac working voltage?
A. 50 V
B. 100 V
C. 200 V
D. 400 V
32. If resonant frequency is 10 kHz and quality factor is 50, then
A. Bandwidth is 200 Hz
B. XL = is 50,000 Ohm
C. R is 50 Ohm
D. XC = is 50,000 Ohm
33. Which statement is true?
A. A series resonant circuit is of high impedance
B. A parallel resonant circuit is of low impedance
C. A series resonant circuit is inductive if it operates at a frequency higher than resonant frequency
D. A parallel resonant circuit is inductive if it operates at a frequency higher than the resonant frequency
34. What is considered as the most important value of a sine wave?
A. Effective value
B. Peak value
C. Average value
D. Instantaneous value
35. An AC series circuit is composed of a resistance of 20 ohm, inductive reactance of 40 ohm, and a capacitive reactance of 15 ohm. If a current of 1 ampere is flowing, what is the applied voltage?
A. 320 V
B. 32 V
C. 220 V
D. 22 V
36. An intermittent and non-symmetrical alternating current like that obtained from the secondary winding of an induction coil
A. Faradic current
B. Transient ac current
C. Inductive current
D. Capacitive current
37. The value of temperature coefficient (alfa) is dependent upon
A. The nature of material and temperature
B. The length of material
C. The cross-sectional area of the material
D. The volume of the material
38. At what frequency will the current in a series RLC circuit reach its maximum value for an applied voltage of 15 V with R = 500 ohm , L = 100 µH and C = 0.001 µF?
A. 403 kHz
B. 503 KHz
C. 603 kHz
D. 303 kHz
39. If two equal resistances connected in series across a certain supply are now connected in parallel across the same supply, the power produced will be __________ that of series connection:
A. One-half
B. Four times
C. One-fourth
D. Two times
40. The voltage lags the current by Pi/2 cycle in a:
A. Purely resistive circuit
B. Purely inductive circuit
C. Purely capacitive circuit
D. Circuit containing resistance, capacitance and inductance
