Electronics MCQs
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Hall effect is observed in a specimen when it is carrying current and is placed in a magnetic field. The resulting electric field inside the speciment will be in
- A. direction normal to both current and magnetic field
- B. the direction of current
- C. direction antiparallel to magnetic field
- D. an arbitrary direction depend upon conductivity
- Correct Answer: Option A
In photoelectric emission the maximum kinetic energy of emitted electron is proportional to
- A. SQRT f
- B. f
- C. f^2
- D. f^3
- Correct Answer: Option B
In a photo transistor the photocurrent is
- A. emitter base junction
- B. collector base junction
- C. collector
- D. either (a) or (b)
- Correct Answer: Option B
Fermi level in intrinsic semiconductor is at the centre of forbidden energy band.
- A. True
- B. False
- Correct Answer: Option A
A varactor diode is
- A. reverse biased
- B. forward biased
- C. biased to breakdown
- D. unbiased
- Correct Answer: Option A
In a triode the potential of grid (with respect to cathode) is usually
- A. zero
- B. negative
- C. positive
- D. zero or positive
- Correct Answer: Option B
Consider the following statements. 1 Etching 2 Exposure to UV radiation 3 Stripping 4 Developing After a wafer has been coated with photo resist the correct sequence of these steps in photolithography is
- A. 2, 4, 3, 1
- B. 2, 4, 1, 3
- C. 4, 2, 1, 3
- D. 3, 2, 3, 1
- Correct Answer: Option C
In a p-n-p transistor operating in forward active mode
- A. base is positive with respect to emitter and collector
- B. base is negative with respect to emitter and collector
- C. emitter is positive with respect to base and base is positive with respect to collector
- D. emitter is negative with respect to base and base is positive with respect to collector
- Correct Answer: Option C
Assertion (A): Field emission is substantially independent of temperature. Reason (R): When a high electric field is created at metal surface field emission may occur.
- A. Both A and R are true and R is correct explanation of A
- B. Both A and R are true but R is not a correct explanation of A
- C. A is true but R is false
- D. A is false but R is true
- Correct Answer: Option B
Consider the following circuit configuration 1 common Emitter 2 common Base 3 emitter follower 4 emitter follower using Darlington pair. The correct sequence in increasing order of I/P impedance of these configuration:
- A. 2, 1, 4, 3
- B. 1, 2, 4, 3
- C. 2, 1, 3, 4
- D. 1, 2, 3, 4
- Correct Answer: Option B