JEE Physics Semiconductor Electronics MCQs Set C

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: If a full wave rectifier circuit is operating from 50 Hz mains, the fundamental frequency in the ripple will be

• a) 100 Hz
• b) 70.7 Hz
• c) 50 Hz
• d) 25 Hz

Answer: 100 Hz

Question: The peak voltage in the output of a half-wave diode rectifier fed with a sinusoidal signal without filter is 10 V. The D.C. component of the output voltage is

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: Which of the following statement is False?

• a) Majority carries in a n-type semiconductors are holes
• b) Pure Si doped with trival ent impurities gives a p-type semiconductor
• c) Minority carries in a p-type semiconductor are electrons
• d) The resistance of intrinisic semiconductor decreases with increase of temperature

Answer: Majority carries in a n-type semiconductors are holes

Question:

• a) Both in region (I) & (III)
• b) In region III
• c) In region I
• d) In region II

Answer: Both in region (I) & (III)

Question:

• a) 10 mV
• b) 0.1 V
• c) 1.0 V
• d) 1 mV

Answer: 10 mV

Question:

• a) 2000
• b) 3000
• c) 4000
• d) 1000

Answer: 2000

Question:

• a) 50
• b) 75
• c) 100
• d) 25

Answer: 50

Question: When NPN transistor is used as an amplifier, then

• a) Electrons move from emitter to base
• b) Holes move from collector to base
• c) Electrons move from collector to base
• d) Holes move from base to collector

Answer: Electrons move from emitter to base

Question: The voltage gain of an amplifier with 9% negative feedback is 10. The voltage gain without feedback will be

• a) 100
• b) 10
• c) 90
• d) 1.25

Answer: 100

Question: An oscillator is nothing but an amplifier with

• a) Positive feedback
• b) Negative feedback
• c) Voltage gain
• d) No feedback

Answer: Positive feedback

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a)

  

• b)

  

• c) 0.01 mA
• d) 0.25 mA

Answer:

Question:

• a) 4.9 × 10¹
• b) 98
• c) 49 × 10^–2
• d) 25.5

Answer: 4.9 × 10¹

Question: A n-p-n transistor conducts in active mode when

• a) Collector is positive and emitter is negative with respect to the base
• b) Both collector and emitter are positive with respect to the base
• c) Collector is positive and emitter is at same potential as the base
• d) Both collector and emitter are negative with respect to the base

Answer: Collector is positive and emitter is negative with respect to the base

Question: A transistor-oscillator using a resonant circuit with an inductor L (of negligible resistance) and a capacitor C in series produce oscillations of frequency f. If L is doubled and C is changed to 4C, the frequency will be

• a)

  

• b)

  

• c)

  

• d) 8f

Answer:

Question:

• a) 1250
• b) 100
• c) 500
• d) 1000

Answer: 1250

Question: The device that can act as a complete electronic circuit is

• a) Integrated circuit
• b) Junction transistor
• c) Junction diode
• d) Zener diode

Answer: Integrated circuit

Question: For transistor action

(a) Base, emitter and collector regions should have similar size and doping concentrations.
(b) The base region must be very thin and lightly doped.
(c) The emitter-base junction is forward biased and base-collector junction is reverse biased.
(d) Both the emitter-base junction as well as the base collector junction are forward biased.
Which one of the following pairs of statements is correct?

• a) (b), (c)
• b) (c), (d)
• c) (a), (b)
• d) (a), (d)

Answer: (b), (c)

Question: In an n-p-n transistor working in active mode, the depletion region

• a) At emitter-base junction is thinner than that at collector-base junction
• b) At emitter-base junction is wider than that at collector-base junction
• c) Is not formed
• d) At the two junctions have equals width

Answer: At emitter-base junction is thinner than that at collector-base junction

Question:

• a) 6 × 10^–2
• b) 6 × 10⁴
• c) 10
• d) 10^–5

Answer: 6 × 10^–2

Question: Which of the conditions must be satisfied to operate a transistor amplifier?

• a) Emitter-base is forward biased junctions collector-base is reverse biased
• b) Emitter-base and collector-base junctions are forward biased
• c) Emitter-base is reverse biased collector-base is forward biased
• d) Emitter-base and collector-base junctions both are reverse biased

Answer: Emitter-base is forward biased junctions collector-base is reverse biased

Question:

• a) 4 mA
• b) 1 mA
• c)

  

• d)

  

Answer: 4 mA

Question:

• a) (ii), (iv) & (iii)
• b) (ii), (iii) & (iv)
• c) (iii), (ii) & (i)
• d) (iii), (ii) & (iv)

Answer: (ii), (iv) & (iii)

Question:

• a) OR gate
• b) NOR gate
• c) NAND gate
• d) AND gate

Answer: OR gate

Question:

• a) NAND
• b) NOR
• c) XOR
• d) OR

Answer: NAND

Question:

• a) NOR gate
• b) XOR gate
• c) OR gate
• d) AND gate

Answer: NOR gate

Question:

• a) NAND gate
• b) OR gate
• c) NOR gate
• d) AND gate

Answer: NAND gate

Question: Which of the following gates will have an output of 1?

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a) AND gate
• b) NAND gate
• c) OR gate
• d) XOR gate

Answer: AND gate

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a) 1
• b) 2
• c) Any of these
• d) 0

Answer: 1

Question:

• a) OR
• b) AND
• c) NAND
• d) NOR

Answer: OR

Question:

• a) XOR gate
• b) NOR gate
• c) NAND gate
• d) AND gate

Answer: XOR gate

Question:

• a) Y = A + B
• b)

  

• c)

  

• d)

  

Answer: Y = A + B

Question: Which of the following is the boolean expression for XOR gate?

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a) It is V-I characteristic for solar cell where point A represents open circuit voltage and point B short circuit current
• b) It is for a solar cell and points A and B represent open circuit voltage and current, respectively
• c) It is for a photodiode and points A and B represent open circuit voltage and current, respectively
• d) It is for an LED and points A and B represent open circuit voltage and short circuit current respectively

Answer: It is V-I characteristic for solar cell where point A represents open circuit voltage and point B short circuit current

Question: The barrier potential of a p-n junction depends on :

a. Type of semiconductor material
b. Amount of doping
c. Temperature
Which one of the following is correct?

• a) a, b and c
• b) b only
• c) b and c only
• d) a and b only

Answer: a, b and c

Question:

• a) AND
• b) NAND
• c) OR
• d) NOR

Answer: AND