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Free download in PDF Class 12 Physics Chapter 14 Semiconductor Electronics Multiple Choice Questions and Answers for Board, JEE, NEET, AIIMS, JIPMER, IIT-JEE, AIEE and other competitive exams. MCQ Questions for Class 12 Physics with Answers were prepared based on the latest exam pattern. These short solved questions or quizzes are provided by Gkseries. These will help the students for preparation of their examination./p>
(1)
A p-type semiconductor is:
[A]
negatively charged3
[B]
positively charged
[C]
uncharged
[D]
None of these
(2)
Zener diode is used for:
[A]
producing oscillations in a oscillator
[B]
amplification
[C]
stabilisation
[D]
rectification
(3)
In full wave rectifier, input a.c. current has a frequency v. The output frequency of current is :
[A]
V/2
[B]
V
[C]
2V
[D]
None
(4)
In semi conductor, at room temperature :
[A]
the valence bond is partially empty and the conduction band is partially filled
[B]
the valence band is completely filled and the conduction band is partially filled
[C]
the valence band is completely filled
[D]
the conduction band is completely empty
Answer: the valence bond is partially empty and the conduction band is partially filled
(5)
Bonds in a semiconductor :
[A]
trivalent
[B]
covalent
[C]
bivalent
[D]
monovalent
(6)
The part of a transistor which is heavily doped to produce a large number of majority carriers is :
[A]
base
[B]
emitter
[C]
collector
[D]
None of these
(7)
What is the number of possible crystal systems?
[A]
5
[B]
7
[C]
14
[D]
16
(8)
The cause of the potential barrier in a p-n junction diode is
[A]
depletion of positive charges near the junction3
[B]
concentration of positive charges near the junction
[C]
depletion of negative charges near the junction
[D]
concentration of positive and negative charges near the junction
Answer: concentration of positive and negative charges near the junction
(9)
Reverse bias applied to a junction diode
[A]
increases the minority carrier current
[B]
lowers the potential barrier
[C]
raises the potential barrier
[D]
increases the majority carrier current
Answer: raises the potential barrier
(10)
In a semiconductor diode, the barrier potential offers opposition to
[A]
holes in P-region only
[B]
free electrons in N-region only
[C]
majority carriers in both regions
[D]
majority as well as minority carriers in both regions
Answer: majority carriers in both regions
(11)
Filter circuit
[A]
eliminates a.c. component
[B]
eliminates d.c. component
[C]
does not eliminate a.c. component
[D]
None of these
Answer: eliminates a.c. component
(12)
In V-I characteristic of a p-n junction, reverse biasing results in
[A]
leakage current
[B]
the current barrier across junction increases
[C]
no flow of current
[D]
large current
(13)
Diffusion current in a p-n junction is greater than the drift current in magnitude)
[A]
if the junction is forward-biased
[B]
if the junction is reverse-biased
[C]
if the junction is unbiased
[D]
in no case
Answer: if the junction is forward-biased
(14)
The drift current in a p-n junction is from the
[A]
n-side to the p-side
[B]
p-side to the n-side
[C]
n-side to the p-side if the junction is forward-biased and in the opposite direction if it is reverse biased
[D]
p-side to the n-side if the junction is forward-biased and in the opposite direction if it is reverse-biased
Answer: n-side to the p-side
(15)
A semiconductor device is connected in a series circuit with a battery and a resistance. A current is found to pass through the circuit. If the polarity of the battery is reversed, the current drops to almost zero. The device may be a/an
[A]
intrinsic semiconductor
[B]
p-type semiconductor
[C]
n-type semiconductor
[D]
p-n junction diode
Answer: p-n junction diode
(16)
A strip of copper and another of germanium are cooled from room temperature to 80K. The resistance of
[A]
each of these decreases
[B]
copper strip increases and that of germanium decreases
[C]
copper strip decreases and that of germanium increases
[D]
each of these increases
Answer: copper strip decreases and that of germanium increases
(17)
The diffusion current in a p-n junction is from the
[A]
n-side to the p-side
[B]
p-side to the n-side
[C]
n-side to the p-side if the junction is forward-biased and in the opposite direction if it is reverse-biased
[D]
p-side to the n-side if the junction is forward-biased and in the opposite direction if it is reverse-biased
Answer: p-side to the n-side
(18)
If the two ends of a p-n junction are joined by a wire
[A]
there will not be a steady current in the circuit
[B]
there will be a steady current from the n-side to the p side
[C]
there will be a steady current from the p-side to the n side
[D]
there may or may not be a current depending upon the resistance of the connecting wire
Answer: there will not be a steady current in the circuit
(19)
Forward biasing is that in which applied voltage
[A]
increases potential barrier
[B]
cancels the potential barrier
[C]
is equal to 1.5 volt
[D]
None of these
Answer: cancels the potential barrier
(20)
If a small amount of antimony is added to germanium crystal
[A]
it becomes a p–type semiconductor
[B]
the antimony becomes an acceptor atom
[C]
there will be more free electrons than holes in the semiconductor
[D]
its resistance is increased
Answer: there will be more free electrons than holes in the semiconductor
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