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WorksheetsMCQs on Semiconductor Physics
Total questions: 25
Worksheet time: 14mins
Intrinsic semiconductors are:
Pure semiconductors
Doped with impurities
Insulators
Conductors
The Fermi level in intrinsic semiconductors lies:
Near the conduction band
In the middle of the energy gap
Near the valence band
Outside the band gap
Electrons and holes recombine in semiconductors releasing:
Sound energy
Light
Magnetic energy
Chemical energy
Mobility of electrons is defined as:
Velocity × electric field
Current density / electric field
Drift velocity / electric field
Charge × resistance
Mobility of charge carriers depends on
temperature
nature of charge carriers
purity of substance
none of them
Drift current occurs due to:
Concentration gradient
Electric field
Temperature gradient
Photon absorption
In a p-n junction, the depletion region has:
Free charge carriers
Ions only
Holes only
Electrons only
The potential barrier in a silicon diode is approximately:
0.1 V
0.3 V
0.5 V
0.7 V
at absolute zero, when energy state is grater than fermi energy level then probability energy state E to be filled with electron will be
0
1
1/2
1/4
A Tunnel diode is known for:
Negative resistance
High forward voltage
Low mobility
High capacitance
A Zener diode is used for:
Amplification
Voltage regulation
Oscillation
Current control
Light Emitting Diode (LED) emits light due to:
Thermal excitation
Electron-hole recombination
Magnetic field
Drift current
A solar cell converts:
Light energy to heat energy
Light energy to electrical energy
Heat energy to electrical energy
Mechanical to electrical energy
In P-type semiconductor, when we increase the doping of acceptor atom, fermi level move towards (a)
The most common transistor type is:
FET
BJT
MOSFET
UJT
in conduction band , if effective mass of electron is nearly zero then
μn>μp
μn<μp
μn=μp
none
In a BJT, base current is:
Zero
Maximum
Very small
Equal to collector current
A pnp transistor has:
Two n regions
Two p regions
One p and two n regions
None
The Fermi-Dirac occupancy probability P (E) varies between:
0 and 1
0 and infinity
1 and infinity
-1 and 1
The Fermi-Dirac occupancy probability P (E) varies between:
0 and 1
0 and infinity
1 and infinity
-1 and 1
The Fermi energy of a metal depends primarily on:
the temperature
the volume of the sample
the mass density of the metal
the number density of conduction electrons
The speed of an electron with energy equal to the Fermi energy for copper is on the order of:
10−6m/s
10m/s
10−1m/s
Application of a forward bias to a p-n junction:
A.narrows the depletion zone
B. increases the electric field in the depletion zone
C. increases the potential difference across the depletion zone
D. increases the number of donors on the n side
With fall of temperature, the forbidden energy gap of a semiconductor
A.increases
B.decreases
C.sometimes increases and sometimes decreases
D.remains unchanged
On applying reverse bias to a junction diode, it:
lowers the potential barrier
raise the potential barrier
increases the majority carrier current
increases the minority carrier current
