Q.1
A hole in a semiconductor is defined as
  • a free electron
  • the incomplete part of an electron pair bond
  • a free proton
  • a free neutron
Q.2
MOSFET can be used as
  • Current controlled capacitor
  • voltage controlled capacitor
  • current controlled indicator
  • voltage controlled indicators
Q.3
MOSFET can be used as a
  • Current controlled capacitor
  • Voltage controlled capacitor
  • Current controlled inductor
  • Voltage controlled inductors
Q.4
What is an energy gap?
  • Space between two orbital shells
  • Energy band in which electrons can move freely
  • Energy level at which an electron can exist
  • None of the above
Q.5
The diode current equation is not applicable in ____________
  • Forward biased state
  • Reverse biased state
  • Unbiased state
  • It is applicable in all bias states
Q.6
In an OP-amp differentiator
  • The amplitude of output is proportional to rate of change of input
  • The amplitude of output is proportional to input
  • Output occurs when input is finite and constant
  • Polarity of input and output is the same
Q.7
Anode is
  • Positive
  • Negetive
  • Chargeless
  • Neutral
Q.8
The current gain of a bipolar transistor drops at high frequencies because of
  • Transistor capacitances
  • High current effects in the base
  • Parasitic inductive elements
  • The early effect
Q.9
Which of the following oscillators is suitable for frequencies in the range of mega hertz?
  • RC phase shift
  • Wien bridge
  • Hartley
  • Both (a) and (c)
Q.10
Thermal runaway is not possible in FET because as the temperature of FET increases
  • The mobility decreases
  • The transconductance increases
  • The drain current increases
  • None of the above
Q.11
In a transistor leakage current mainly depends on
  • Doping of base
  • Size of emitter
  • Rating of transistor
  • Temperature
Q.12
The cascade amplifier is a multistage configuration of
  • CC-CB
  • CE-CB
  • CB-CC
  • CE-CC
Q.13
What will happen if doping of an intrinsic semiconductor with pentavalent impurity atom ?
  • Fermi level not change
  • Fermi level fall
  • Fermi level raises
  • All of the above
Q.14
The early effect in a bipolar junction transistor is caused by
  • Fast turn-on
  • Fast turn-off
  • Large collector-base reverse bias
  • Large emitter-base forward bias
Q.15
The current gain of a BJT is
  • gm r0
  • gm / r0
  • gm rπ
  • gm /rπ
Q.16
In a CE amplifier the input impedance is equal to the ratio of
  • ac base voltage to ac base current
  • ac base voltage to ac emitter current
  • ac emitter voltage to ac collector current
  • ac collector voltage to ac collector current
Q.17
A change in the value of the emitter resistance Re in a differential amplifier
  • Affects the difference mode gain Ad
  • Affects the common mode gain Ac
  • Affects both Ad and Ac
  • Does not effect either Ad and Ac
Q.18
In a CB amplifier the maximum efficiency could be
  • 99%
  • 85%
  • 50%
  • 25%
Q.19
In a half wave rectifier, the input sine wave is 250sinᴨt Volts. The output ripple frequency of rectifier will be __________
  • 100 Hz
  • 200 Hz
  • 50 Hz
  • 25 Hz
Q.20
AV power supply would use which filter capacitor?
  • paper capacitor
  • electrolytic capacitor
  • mica capacitor
  • air capacitor
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