set 5 MCQ Questions & Answers Detailed Explanation

Question : 1

In a p-n junction

a) the p side is at higher electrical potential than n side

b) the n side is at higher electric potential than p side

c) the potential of p & n sides becomes higher alternately

d) both p & n sides are at same potential

Question : 2

Match list-I with list -II:

a) 2 1 4 3

b) 3 1 4 2

c) 3 4 1 2

d) 2 4 1 3

Question : 3

Which one among the following is the correct order of power consumption for light of equal intensity ?

a) CFL tube < Fluorescent tube < Light emitting diode < Incandescent bulb

b) CFL tube < Fluorescent tube < Incandescent bulb < Light emitting diode

c) Light emitting diode < CFL tube < Fluorescent tube < Incandescent bulb

d) Incandescent bulb < Light emitting diode < Fluorescent tube < CFL tube

Question : 4

Consider the following statements. An ordinary light bulb has a rather short life because the

1. Filament wire is not uniform.
2. Bulb cannot be evacuated completely.
3. Wires supporting the filament melt at high temperatures.

a) 1 and 3

b) 1 and 3

c) 2 and 3

d) 1, 2 and 3

Question : 5

The Donor level in a semiconductor is placed

a) in the forbidden energy gap close to the upper edge of the valence band

b) in the conduction band close to the lower edge to the conduction band

c) half-way in the forbidden energy gap

d) in the forbidden energy gap close to the lower edge of the conduction band

Question : 6

To obtain a p-type germanium semiconductor, it must be doped with

a) antimony

b) indium

c) arsenic

d) phosphorus