In a p-n junction diode at equilibrium, which one of the following statements is NOT TRUE?

The hole and electron diffusion current components are in the same direction.

The hole and electron drift current components are in the same direction.

On an average, holes and electrons drift in opposite direction.

On an average, electrons drift and diffuse in the same direction.

Charge carriers can move in semiconductor via:

Both drift and diffusion mechanism

Explore topic-wise MCQs in Electronic Devices Circuits.

This section includes 8 Mcqs, each offering curated multiple-choice questions to sharpen your Electronic Devices Circuits knowledge and support exam preparation. Choose a topic below to get started.

1.	In a PNP transistor, due to doping the emitter conductivity is 10 times base conductivity. Electron diffusion length in a more heavily doped emitter is half the hole diffusion length in the base. The base width is one-tenth of the hole diffusion length in the base. The a and b of the transistor are _____ and ______.
A.	a = 0.976, b = 40.7
B.	a = 0.976, b = 2
C.	a = 1.025, b = 4.1
D.	a = 1.025, b = 40.7
Answer» B. a = 0.976, b = 2

Discussion

2.	In a p-n junction diode at equilibrium, which one of the following statements is NOT TRUE?
A.	The hole and electron diffusion current components are in the same direction.
B.	The hole and electron drift current components are in the same direction.
C.	On an average, holes and electrons drift in opposite direction.
D.	On an average, electrons drift and diffuse in the same direction.
Answer» E.

Discussion

3.	If σ = 4.0/m and E = 5.0 V/m, conduction current density is:
A.	10.0 A/m2
B.	5.0 A/m2
C.	1.25 A/m2
D.	20.0 A/m2
Answer» E.

Discussion

4.	Consider electron and hole mobilities of germanium at 300 K is 0.36 m2/Vs and 0.17 m2/Vs respectively and hole and electron concentration of 2.7 × 1019 per m3. Find the conductivity of germanium at 300 K.
A.	1.4 mho/m
B.	2.3 mho/m
C.	1.3 mho/m
D.	2.0 mho/m
Answer» C. 1.3 mho/m

Discussion

5.	An n type silicon that is 1 μm long senses a voltage of 1 V. If the mobility of the electrons μn = 1350 cm2 / V-s the velocity of the electron is:
A.	1350 cm/s
B.	1.35 × 106 cm/s
C.	1.35 × 107 cm/s
D.	1.35 × 103 cm/s
Answer» D. 1.35 × 103 cm/s

Discussion

6.	Charge carriers can move in semiconductor via:
A.	Diffusion mechanism
B.	Floating mechanism
C.	Drift mechanism
D.	Both drift and diffusion mechanism
Answer» E.

Discussion

7.	At a temperature of 298 Kelvin, Silicon is not suitable for most electronic applications, due to a small amount of conductivity. This can be altered by
A.	Gettering
B.	Doping
C.	Squeezing
D.	Sintering
Answer» C. Squeezing

Discussion

8.	In a long p-type Si-bar with cross-sectional area = 0.5 cm2 and Na = 2 × 1017 cm-3, extra holes = 1016 cm-3 are injected. Assume μp = 500 cm2/Vs, ni = 1010 cm-3 and τp = 10-10 s, find minority carrier lifetime.
A.	10 μs
B.	15 μs
C.	20 μs
D.	Data insufficient
Answer» E.

Discussion

Explore topic-wise MCQs in Electronic Devices Circuits.

In a p-n junction diode at equilibrium, which one of the following statements is NOT TRUE?

If σ = 4.0/m and E = 5.0 V/m, conduction current density is:

Consider electron and hole mobilities of germanium at 300 K is 0.36 m2/Vs and 0.17 m2/Vs respectively and hole and electron concentration of 2.7 × 1019 per m3. Find the conductivity of germanium at 300 K.

An n type silicon that is 1 μm long senses a voltage of 1 V. If the mobility of the electrons μn = 1350 cm2 / V-s the velocity of the electron is:

Charge carriers can move in semiconductor via:

At a temperature of 298 Kelvin, Silicon is not suitable for most electronic applications, due to a small amount of conductivity. This can be altered by

In a long p-type Si-bar with cross-sectional area = 0.5 cm2 and Na = 2 × 1017 cm-3, extra holes = 1016 cm-3 are injected. Assume μp = 500 cm2/Vs, ni = 1010 cm-3 and τp = 10-10 s, find minority carrier lifetime.