Questions and Answers on Electrical Engineering

1-The power consumed by an electrical device is 1000W at 250V. What is the resistance in the device?
(A) 60 ohm
(B) 250000 ohm
(C) 4 ohm
(D) 62.5 ohm
2-The capacitance of a parallel plate capacitor increases with
(A) larger plate area and shorter distance between plates
(B) smaller plate area and shorter distance between plates
(C) smaller plate area and higher applied voltage
(D) larger plate area, larger distance between plates and higher applied voltages
3-Two heaters of rating 1KW, 250V are connected in series across 250V supply, the power taken by the heaters will be
(A) 2 KW
(B) ¼ KW
(C) ½ KW
(D) 1 KW
4-If V=a+jb and I=c+jd, then power is given by
(A) ac+ad
(B) ac+bd
(C) bc-ad
(D) bc+ad
5-The ratio of charge stand by two metallic spheres raised to the same potential is 6. The ratio of the surfaces areas of the spheres is
(A) 6
(B) 1/6
(C) 1/√6
(D) 36
6-▼.B is based on
(A) Ampere’s law
(B) Ohm’s law
(C) Faraday’s law
(D) Gauss’s law
7-The following law is synonymous to the occurrence of diamagnetism
(A) Gauss’s law
(B) Lenz’s law
(C) Maxwell’s law
(D) Kirchoff’s law
8-The transfer function of an integral compensator is given by
(A) 1/s
(B) 1/s²
(C) k/s
(D) None of the above
9-The following is the range of power consumption in PMMC instrument.
(A) 0.25W to 2W
(B) 0.25mW to 2mW
(C) 25μW to 200μW
(D) 2W to 3W
10-Frequency can be measured by using
(A) Maxwell’s Bridge
(B) Schering Bridge
(C) Heaviside Campbell bridge
(D) Wein’s bridge
11-Maxwell’s inductance capacitance bridge is used for measurement of inductance of
(A) low Q coils
(B) medium Q coils
(C) high Q coils
(D) low and medium Q coils
12-The following amplifier configuration yields the largest power gain of all transistor amplifier configurations.
(A) Common base
(B) Common emitter
(C) Common collector
(D) Emitter base
13-Which family of logic circuits used FETs?
(A) TTL
(B) CMOS
(C) Both TTL and CMOS
(D) None of the above
14-Common Mode Rejection ratio (CMRR) for a differential amplifier is the ratio of
(A) Differential gain / Common mode gain
(B) Differential gain / Integrated gain
(C) Integrated gain / Differential gain
(D) Common mode gain / Differential gain
15-Which of the following is the most stable oscillator?
(A) Wein’s bridge oscillator
(B) Hartley’s oscillator
(C) Colpitt’s oscillator
(D) Crystal oscillator
16-The number of bits needed to address 4kb memory is
(A) 6
(B) 8
(C) 12
(D) 16
17-The generation of harmonics in transformer is mainly due to
(A) Fluctuating load
(B) Poor insulation
(C) Mechanical vibrations
(D) Saturation of core
18-If the capacitor of a single phase motor is short circuited
(A) The motor will not start
(B) The motor will run
(C) The motor will run in reverse direction
(D) The motor will run in the same direction at reduced RPM
19-A chopper can be used on
(A) Pulse width modulation only
(B) Frequency modulation only
(C) Amplitude modulation only
(D) both (A) and (C)
ANSWERS:
1-(D), 2-(A), 3-(C), 4-(B), 5-(A), 6-(A), 7-(B), 8-(C), 9-(C), 10-(D), 11-(A), 12-(B), 13-(B), 14-(A), 15-(D), 16-(C), 17-(D), 18-(A), 19-(D)