Electronic Devices And Circuits - Study Mode

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[#71] Number of electron-hole pairs generated per incident photon is called . . . . . . . .

(A) Power efficiency

(B) Luminescence efficiency

(C) Optical efficiency

(D) Frequency response

Correct Answer

Power efficiency

[#72] The best electronic device for fast switching is

(A) BJT

(B) triac

(C) JFET

(D) MOSFET

Correct Answer

(D) MOSFET

[#73] In an extrinsic semiconductor the conductivity significantly depends upon:

(A) Majority charge carriers generated due to impurity doping

(B) Minority charge carriers generated due to thermal agitation

(C) Majority charge carriers generated due to thermal agitation

(D) Minority charge carriers generated due to impurity doping

Correct Answer

(A) Majority charge carriers generated due to impurity doping

[#74] Consider the following statements regarding the formation of P-N junctions: 1. Holes diffuse across the junction from P-side to N-side. 2. The depletion layer is wiped out. 3. There is continuous flow of current across the junction. 4. A barrier potential is set up across the junction. Which of the above statements are correct?

(A) 1 and 3

(B) 2 and 3

(C) 1 and 4

(D) 2 and 4

Correct Answer

(C) 1 and 4

[#75] The doping concentration on the p-side and n-side of a silicon diode are 1 × 10 16 cm -3 , and 1 × 10 17 cm -3 respectively. A forward bias of 0.3 V is applied to the diode. At T = 300 K, the intrinsic carrier concentration of silicon n i = 1.5 × 10 10 cm -3 and $$frac{{{ ext{kT}}}}{{ ext{q}}}$$ = 26mV. The electron concentration at the edge of the depletion region on the p-side is

(A) 2.3 × 10 9 cm -3

(B) 1 × 10 16 cm -3

(C) 1 × 10 17 cm -3

(D) 2.25 × 10 6 cm -3

Correct Answer

(A) 2.3 × 10 9 cm -3