AC FUNDAMENTALS MCQs Part 05

41. Which will draw least current
a. 40 W lamp
b. 40-W tube light
c. 40 W induction motor

42. The instantaneous value of current i at t = 0.35 ms will be
a. 10.1 mA
b. 20.5 mA
c. 205 mA
d. 101 mA

43. What value of dc voltage will produce the same average power as 150 V peak sine wave
a. 144 V
b. 121 V
c. 111 V
d. 106 V

44. What current will an ammeter show when connected in series with a 32 ohm load that is dissipating a peak power of 288 W?
a. 1.06
b. 2.12 A
c. 4.24 A
d. 8.48 A

45. A 160 W soldering iron is operated from the 60 Hz power line. The resistance of the soldering iron is
a. 10 ohms
b. 25.5 ohms
c. 51.5 ohms
d. 75.6 ohms

46. A certain 1-KHz sine wave reaches – 70 V at t = 0.6 ms . The peak value of this sine wave will be
a. 100 V
b. 114 V
c. 141.4 V
d. 118 V

47. In a.c circuits the a.c meters measure
a. r.m.s values
b. peak values
c. mean value
d. mean square value

48. Radio frequency choke is air – cored to
a. keep frequency low
b. keep frequency high
c. keep inductive reactance low
d. keep inductance reactance high

49. Hot wire ammeters are used for measuring
a. both a.c and d.c
b. only a.c
c. only d.c
d. neither a.c nor d.c

50. A choke coil is used for controlling current in an
a. a.c circuit only
b. d.c circuit only
c. both a.c and d.c circuits
d. Integrated circuits

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