Objective Type Question or MCQ of Electrical Circuits and Magnetic Fields page-3
31. The average value of the alternating current is more than the r.m.s. value
a) True
b) False
Ans: (b)
32. The amplitude factor of sinusoidal voltage is
a) 1.11
b) 1.57
c) 1.414
d) 0.637
e) 0.707
Ans: (c)
33. An electrical circuit is shown below, what will be the power dissipation in the circuit assuming P as power across R2 ?
a) 3/4 P
b) 2/3 P
c) 4/3 P
d) 3/2 P
Ans: (c)
34. The resistance of a few meters of wire conductor in closed electrical circuit is
a) Very high
b) Practically zero
c) A few thousand ohm
d) Close to 10,000 ohms
Ans: (b)
35. If two resistances connected in parallel and each dissipates 10 watts the total power supplied by the voltage source equals
a) 5 watts
b) 10 watts
c) 20 watts
d) 100 watts
Ans: (c)
36. If a parallel circuit is open in the main line, the current
a) Increases in each branch
b) Is zero in all branches
c) Is zero in the highest resistive branch
d) Increases in the branch of the lowest resistance
Ans: (b)
37. In a series parallel circuit, any two resistances in the same current path must be in
a) Parallel with each other
b) Parallel with the voltage source
c) Series with the voltage source
d) Series with each other
Ans: (d)
38. In a series parallel circuit with 6 resistances if there are three in one parallel bank, these three resistances must have
a) The same current as in the voltage source
b) The same current
c) The same IR drop
d) An IR drop equal to the applied voltage
Ans: (c)
39. In which of the following circuits most current will be produced by the voltage source?
a) 5 volts across a 5 ohm resistance
b) 5 volts across two 5 ohm resistance in series
c) 5 volts across two 5 ohm resistance in parallel
d) 500 volts across a 1 M Ω resistance
Ans: (c)
40. There 60 watt bulbs are in parallel across the 60 volt power line. If one bulbs burns open
a) Rest of the two bulbs will not light
b) All three bulbs will light
c) The other two bulbs will light
d) There will be heavy current in the main line
Ans: (c)
41. If a wire conductor of 0.1 ohm resistance is doubled in length, its resistance becomes
a) 0.1 ohm
b) 0.02 ohm
c) 0.2 ohm
d) 0.05 ohm
Ans: (c)
42. The hot resistance of the bulbs’s filament is higher than its cold resistance because the temperature coefficient of the filament is
a) Negative
b) Zero
c) Positive
d) About 5 ohms per degree
Ans: (c)
43. The square waveform of current has following relation between r.m.s. value and average value
a) R.M.S. value of current is greater than the average value
b) R.M.S. value of current is less than the average value
c) R.M.S. value of the current is to average value
d) There is no meaning of r.m.s value and average value for square wave
Ans: (c)
44. There are not transient in resistive circuits.
a) True
b) False
Ans: (a)
45. Transient currents are not driven by any part of the applied voltage to circuit.
a) True
b) False
Ans: (a)