Semiconductor Physics and Diodes MCQs

Question 1

In any atom, the potential energy of an orbiting electron is

Accepted Answer

always negative

Answer

always positive

Answer

sometime positive, sometime negative

Answer

numerically less than its kinetic energy

Question 2

Regarding valence band in a solid which statement is false?

Accepted Answer

it may be empty in some solids

Answer

it represents the energy possessed by the valence electrons

Answer

it is the highest occupied band

Answer

it is either completely filled or partially filled

Question 3

Which statement regarding conduction band is false?

Accepted Answer

it lies below the valence band

Answer

it is the lowest unfilled energy band

Answer

it represents the energy of conduction electrons

Answer

it may be eitherempty or partially filled

Question 4

The neighbouring atoms in the crystalline lattice structure of a semiconductor like Ge form ? bonds.

Accepted Answer

covalent

Answer

ionic

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metallic

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molecular

Question 5

Intrinsic semiconductors are those which

Accepted Answer

have zero energy gap

Answer

are available locally

Answer

are made of the semiconductor material in its purest form

Answer

have more electrons than holes

Question 6

In an N-type semiconductor, the position of the Fermi level

Accepted Answer

(e) can be anywhere depending upon the doping concentration

Answer

is lower than the centre of the energy gap

Answer

is at the centre of the energy gap is higher than the centre of the energy gap

Answer

none of these

Question 7

In order to obtain a p-type germanium, the germanium should be doped with a

Accepted Answer

pentavalent impurity

Answer

trivalent impurity

Answer

tetravalent impurity

Answer

any of the above will do

Question 8

For converting intrinsic semiconductor into N-type extrinsic semiconductor, which of the following doping elements would not be suitable?

Accepted Answer

indium

Answer

arsenic

Answer

antimony

Answer

phosphorous

Question 9

Consider the energy level diagram of an intrinsic semiconductor. The Fermi level lies in the

Accepted Answer

forbidden gap

Answer

valence band

Answer

conduction band or

Answer

it can be at any of the above locations depending upon the doping concentration and temperature