The most commonly used semiconductor material is
A. Silicon
B. Germanium
C. Mixture of silicon and germanium
D. None of the above
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Permalloy is
A. A variety of stainless steel
B. A polymer
C. A conon-ferrous alloy used in aircraft industry
D. A nickel an iron alloy having high permeability
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Which one of the following is not a characteristic of a ferroelectric material?
A. High dielectric constant
B. No hysteresis
C. Ferroelectric characteristic only above the curie point
D. Electric dipole moment
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In which of these is reverse recovery time nearly zero?
A. Zener diode
B. Tunnel diode
C. Schottky diode
D. PIN diode
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Hall effect is observed in a specimen when it is carrying current and is placed in a magnetic field. The resultant electric field inside the specimen is
A. Normal to both current and magnetic field
B. In the direction of current
C. Antiparallel to magnetic field
D. In arbitrary direction
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Fermi level is the amount of energy in which
A. A hole can have at room temperature
B. An electron can have at room temperature
C. Must be given to an electron move to conduction band
D. None of the above
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In monolithic ICs, all the components are fabricated by
A. Diffusion process
B. Oxidation
C. Evaporation
D. None
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When diodes are connected in series to increase voltage rating the peak inverse voltage per junction
A. should not exceed half the breakdown voltage
B. should not exceed the breakdown voltage
C. should not exceed one third the breakdown voltage
D. may be equal to or less than breakdown voltage
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If fixed positive charges are present in the gate oxide of an n-channel enhancement type MOSFET, it will lead to
A. a decrease in the threshold voltage
B. channel length of modulation
C. an increase in substrate leakage current
D. an increase in accumulation capacitance
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The main drawback of JFET is its
A. High input impedance
B. Low input impedance
C. Higher noise
D. Lower gain
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If a donor type impurity is added to the semiconductor, then at a given temperature, the Fermi Level
A. Moves towards the center of the energy gap
B. Moves towards the valence band
C. Moves towards the conduction band
D. Doesn't change
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In PN junction diode, P side is doped with acceptor concentration of 2 × 1016 cm-3 , N side is doped donor concentration of 5 × 1017 cm-3 . The contact potential of diode is:
Assume thermal equivalent voltage equal to 26 mV and intrinsic carrier concentration equal to 1.45 × 1010 cm-3 .
A. 0.82 V
B. 0.2 V
C. 1.2 V
D. 0 V
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The forward amplification factor of a transistor corresponds to
A. the power gain of CE amplifier
B. the current gain of CB amplifier
C. the voltage gain of CC amplifier
D. the voltage gain of CE amplifier
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A diode which resembles a voltage variable capacitor is known as
A. Tunnel diode
B. Schottky diode
C. PIN diode
D. Varactor diode
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Find the wrong statement: specific heat of a material is
A. constant
B. heat capacity per unit mass
C. extrinsic property
D. of units as Joule/Kg-K
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The capacitance of a reverse-biased PN junction
A. Increases as the reverse bias is decreased
B. Increases as the reverse bias is increased
C. Depends mainly on the reverse saturation current
D. None of these
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Thermionic emission occurs in
A. Transistors
B. Ferrite cores
C. Copper conductors
D. Vacuum tubes
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The stability of fixed bias circuit
A. good
B. poor
C. excellent
D. can't predict
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Most of the majority carriers from the emitter . . . . . . . .
A. recombine in the base
B. recombine in the emitter
C. pass through the base region to the collector
D. none of the above
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The Integrated Circuit used in computers is made of which element?
A. Silica
B. Chromium
C. Iron Oxide
D. Silicon
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