Semiconductor Physics and Diodes MCQs

Question 1

At higher forward voltages, a junction diode is likely to

Accepted Answer

burn out

Answer

get saturated

Answer

suffer breakdown

Answer

become noisy

Question 2

A general purpose diode is more likely to suffer avalanche breakdown rather than Zener breakdown because

Accepted Answer

it is lightly-doped

Answer

its leakage current is small

Answer

it has stroug covalent bands

Answer

it has low reverse resistance

Question 3

The static V/I characteristics of a junction diode can be described by the equation called

Accepted Answer

Boltzmann diode equation

Answer

Richardson-Dushman equation

Answer

Einstein's photoelectic equation

Answer

Child's three half-power law

Question 4

The turn-on voltage of a Ge junction diode is ___ volt.

Accepted Answer

0.3

Answer

0.7

Answer

1

Answer

0.1

Question 5

For converting intrinsic semiconductors into extrinsic ones, the level of doping required is about

Accepted Answer

1 : 108

Answer

1 : 103

Answer

1 : 105

Answer

0.111805556

Question 6

At 0?K, a pure semiconductor behaves like an insulator because

Accepted Answer

no free electrons are available for current conduction

Answer

drift velocity of free electrons is very small

Answer

energy possessed by electrons at that low temperature is almost zero

Answer

there is no recombination of electrons with holes

Question 7

The energy gap is much more in silicon than in germanium because

Accepted Answer

its valence electrons are more tightly bound to their parent nuclei

Answer

its crystal has much stronger bonds called ionic bonds

Answer

it has high atomic mass number

Answer

it has less number of electrons

Question 8

The temperature coefficient of an intrinsic semiconductor is

Accepted Answer

negative

Answer

positive

Answer

zero

Answer

like that of metals

Question 9

Barrier potential in a P-N junction is caused by

Accepted Answer

diffusion of majority carriers across the junction

Answer

thermally-generated electrons and holes

Answer

migration of minority carriers across the junction

Answer

flow of drift current