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Free download in PDF PN Junction Diode Objective Type Questions and Answers for competitive exams. These short objective type questions with answers are very important for Board exams as well as competitive exams. These short solved questions or quizzes are provided by Gkseries.
(21)
The depletion region of a PN junction is one that is depleted of
[A]
Mobile charges
[B]
Immobile charges
[C]
Atoms
[D]
None of the above
(22)
A reverse-biased PN junctions has
[A]
Almost zero current
[B]
A very narrow depletion layer
[C]
A net electron current
[D]
A net hole current
Answer: Almost zero current
(23)
The main reason why electrons can tunnel through a PN junction is that
[A]
Depletion layer is extremely thin
[B]
Impurity level is low
[C]
They have high energy
[D]
Barrier potential is very low
Answer: Depletion layer is extremely thin
(24)
In a reverse biased PN junction, the current through the junction increases abruptly at
[A]
Breakdown voltage
[B]
0.72 V
[C]
0.5 V
[D]
1.1 V
Answer: Breakdown voltage
(25)
As a PN junction is forward biased
[A]
The depletion region decreases
[B]
The barrier tends to breakdown
[C]
Holes as well as electrons tend to drift away from the junction
[D]
None of the above
Answer: The depletion region decreases
(26)
PN junction failure below 5 V is caused primarily by
[A]
Avalanche breakdown
[B]
Zener breakdown
[C]
Either of (a) and (b) above
[D]
None of the above
(27)
A PN junction
[A]
Conducts in forward direction only
[B]
Has high resistance in forward as well as reverse directions
[C]
Has low resistance in forward as well as reverse directions
[D]
Conducts in reverse direction only
Answer: Conducts in forward direction only
(28)
A PN junction is said to be forward biased when
[A]
Positive terminal of the battery is connected to P-side and the negative side to the N-side
[B]
Junction is earthed
[C]
N-side is connected directly to the p-side
[D]
Positive terminal of the battery is connected to N-side and the negative side to the P-side
Answer: Positive terminal of the battery is connected to P-side and the negative side to the N-side
(29)
In a PN junction when the applied voltage overcomes the ........ potential, the diode current is large, which is known as .............
[A]
Barrier, forward bias
[B]
Resistance, reverse bias
[C]
Depletion, negative bias
[D]
Reverse, reverse bias
Answer: Barrier, forward bias
(30)
When a PN junction is reverse-biased
[A]
Holes and electrons tend to concentrate towards the junction
[B]
The barrier tends to break down
[C]
Holes and electrons tend to move away from the junction
[D]
None of the above
Answer: Holes and electrons tend to move away from the junction
31
When PN junction is in forward bias, by increasing the battery voltage
[A]
Current through P-N junction increases
[B]
Current through P-N junction decreases
[C]
Circuit resistance increases
[D]
None of the above happens
Answer: Current through P-N junction increases
32
In an unbiased PN junction
[A]
The junction current is due to minority carriers only
[B]
The junction current at equilibrium is zero as equal but opposite carriers are crossing the junction
[C]
The junction current reduces with rise in temperature
[D]
The junction current at equilibrium is zero as charges do not cross the junction
Answer: The junction current at equilibrium is zero as equal but opposite carriers are crossing the junction
33
In a PN junction with no external voltage, the electric field between acceptor and donor ions is called a
[A]
Barrier
[B]
Threshold
[C]
Peak
[D]
Path
34
In a PN junction the potential barrier is due to the charges on either side of the junction, these charges are
[A]
Majority carriers
[B]
Minority carriers
[C]
Both (a) and (b)
[D]
Fixed donor and acceptor ions
Answer: Fixed donor and acceptor ions
35
Diode characteristic curve is a plot between
[A]
current and time
[B]
voltage and time
[C]
voltage and current
[D]
both a and b
Answer: voltage and current
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