HPCL/BPCL/IOCL Engineering Assistant Sample Question Paper – For Electrical & Electronics Engineering
1. Removing bypass capacitor across the emitter-leg resistor in a CE amplifier causes
(a) increase in current gain.
(b) decrease in current gain.
(c) increase in voltage gain.
(d)decrease in voltage gain.
Ans- (d)
2. When a step-input is given to an op-amp integrator, the output will be
(a) a ramp.
(b) a sinusoidal wave.
(c) a rectangular wave.
(d) a triangular wave with dc bias.
Ans- (a)
3. Hysteresis is desirable in Schmitt-trigger, because
(a) energy is to be stored/discharged in parasitic capacitances.
(b) effects of temperature would be compensated.
(c) devices in the circuit should be allowed time for saturation and desaturation.
(d) it would prevent noise from causing false triggering.
Ans- (c)
4. Space charge region around a p-n junction
(a) does not contain mobile carriers
(b) contains both free electrons and holes
(c) contains one type of mobile carriers depending on the level of doping of the p or n regions
(d) contains electrons only as free carriers
Ans- (c)
5. When an amplifier is provided with current series feedback, its
(a) input impedance increases and output impedance decreases
(b) input and output impedances both decrease
(c) input impedance decreases and output impedance increases
(d) input and output impedances both increase
Ans- (d)
6. The fan-out of a MOS-logic gate is higher than that of TTL gates because of its
(a) low input impedance
(b) high output impedance
(c) low output impedance
(d) high input impedance
Ans-(d)
7. A highly stable resonance characteristic is the property of a ____ oscillator.
(a) Hartley
(b) Colpitts
(c) Crystal
(d) Weinbridge
Ans. (c)
8. A phase shift oscillator uses __________________.
(a) LC tuning
(b) Piezoelectric crystal
(c) Balanced bridge
(d) Variable frequency operation
Ans. (c)
9. A bistable multivibrator is a
(a) Free running oscillator.
(b) Triggered oscillator.
(c) Saw tooth wave generator.
(d) Crystal oscillator
Ans-(b)
10. The number of point to point links required in a fully connected network for 50 entities is
(a) 1250
(b) 1225
(c) 2500
(d) 50
Ans- (c)
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