Olete.in – MCQs, Mock Tests & Government Job Prep | Semiconductor Semiconductor Mcq Question Set 1

A semiconductor is formed by ……… bonds.

1. Covalent
2. Electrovalent
3. Co-ordinate
4. none of the above

✅ Correct Answer: 1

A semiconductor has ………… temperature coefficient of resistance.

1. Positive
2. Zero
3. Negative
4. none of the above

✅ Correct Answer: 3

The most commonly used semiconductor is ………..

1. Germanium
2. Silicon
3. Carbon
4. Sulphur

✅ Correct Answer: 2

A semiconductor has generally ……………… valence electrons.

1. 2
2. 3
3. 6
4. 4

✅ Correct Answer: 4

The resistivity of pure germanium under standard conditions is about ……

1. Ω cm
2. 60
3. Ω cm
4. 3 x 106

✅ Correct Answer: 1

The resistivity of a pure silicon is about ……

1. 100 Ω cm
2. 6000 Ω cm
3. 3 x 105 Ω m
4. 6 x 10-8 Ω cm

✅ Correct Answer: 2

When a pure semiconductor is heated, its resistance ……

1. Goes up
2. Goes down
3. Remains the same
4. Can’t say

✅ Correct Answer: 2

The strength of a semiconductor crystal comes from ……

1. Forces between nuclei
2. Forces between protons
3. Electron-pair bonds
4. none of the above

✅ Correct Answer: 3

When a pentavalent impurity is added to a pure semiconductor, it becomes …

1. An insulator
2. An intrinsic semiconductor
3. p-type semiconductor
4. n-type semiconductor

✅ Correct Answer: 4

Addition of pentavalent impurity to a semiconductor creates many ……

1. Free electrons
2. Holes
3. Valence electrons
4. Bound electrons

✅ Correct Answer: 1

A pentavalent impurity has ………. Valence electrons

1. 3
2. 5
3. 4
4. 6

✅ Correct Answer: 2

An n-type semiconductor is ………

1. Positively charged
2. Negatively charged
3. Electrically neutral
4. none of the above

✅ Correct Answer: 3

A trivalent impurity has ….. valence electrons

1. 4
2. 5
3. 6
4. 3

✅ Correct Answer: 4

Addition of trivalent impurity to a semiconductor creates many ……..

1. Holes
2. Free electrons
3. Valence electrons
4. Bound electrons

✅ Correct Answer: 1

A hole in a semiconductor is defined as ………

1. A free electron
2. The incomplete part of an electron pair bond
3. A free proton
4. A free neutron

✅ Correct Answer: 2

The impurity level in an extrinsic semiconductor is about ….. of pure semiconductor.

1. 10 atoms for 108 atoms
2. 1 atom for 108 atoms
3. 1 atom for 104 atoms
4. 1 atom for 100 atoms

✅ Correct Answer: 2

As the doping to a pure semiconductor increases, the bulk resistance of the semiconductor ……

1. Remains the same
2. Increases
3. Decreases
4. none of the above

✅ Correct Answer: 3

A hole and electron in close proximity would tend to ……

1. Repel each other
2. Attract each other
3. Have no effect on each other
4. none of the above

✅ Correct Answer: 2

In a semiconductor, current conduction is due to ……..

1. Only holes
2. Only free electrons
3. Holes and free electrons
4. none of the above

✅ Correct Answer: 3

The random motion of holes and free electrons due to thermal agitation is called ……

1. Diffusion
2. Pressure
3. Ionisation
4. none of the above

✅ Correct Answer: 1

A forward biased pn junction diode has a resistance of the order of

1. Ω
2. kΩ
3. MΩ
4. none of the above

✅ Correct Answer: 1

The battery connections required to forward bias a pn junction are ……

1. +ve terminal to p and –ve terminal to n
2. -ve terminal to p and +ve terminal to n
3. -ve terminal to p and –ve terminal to n
4. none of the above

✅ Correct Answer: 1

The barrier voltage at a pn junction for germanium is about ………

1. 5 V
2. 3 V
3. Zero
4. 3 V

✅ Correct Answer: 4

In the depletion region of a pn junction, there is a shortage of ……..

1. Acceptor ions
2. Holes and electrons
3. Donor ions
4. none of the above

✅ Correct Answer: 2

A reverse bias pn junction has ……

1. A reverse bias pn junction has ……
2. Almost no current
3. Very low resistance
4. Large current flow

✅ Correct Answer: 2

A pn junction acts as a ………

1. Controlled switch
2. Bidirectional switch
3. Unidirectional switch
4. none of the above

✅ Correct Answer: 3

A reverse biased pn junction has resistance of the order of

1. Ω
2. kΩ
3. MΩ
4. none of the above

✅ Correct Answer: 3

The leakage current across a pn junction is due to ……

1. Minority carriers
2. Majority carriers
3. Junction capacitance
4. none of the above

✅ Correct Answer: 1

When the temperature of an extrinsic semiconductor is increased, the pronounced effect is on……

1. Junction capacitance
2. Minority carriers
3. Majority carriers
4. none of the above

✅ Correct Answer: 2

With forward bias to a pn junction , the width of depletion layer ………

1. Decreases
2. Increases
3. Remains the same
4. none of the above

✅ Correct Answer: 1

The leakage current in a pn junction is of the order of

1. Aa
2. mA
3. kA
4. µA

✅ Correct Answer: 4

In an intrinsic semiconductor, the number of free electrons ………

1. Equals the number of holes
2. Is greater than the number of holes
3. Is less than the number of holes
4. none of the above

✅ Correct Answer: 1

At room temperature, an intrinsic semiconductor has ……….

1. Many holes only
2. A few free electrons and holes
3. Many free electrons only
4. No holes or free electrons

✅ Correct Answer: 2

At absolute temperature, an intrinsic semiconductor has ……….

1. A few free electrons
2. Many holes
3. Many free electrons
4. No holes or free electrons

✅ Correct Answer: 4

At room temperature, an intrinsic silicon crystal acts approximately as …

1. A battery
2. A conductor
3. An insulator
4. A piece of copper wire

✅ Correct Answer: 3

Under normal conditions a diode conducts current when it is ……

1. reverse biased
2. forward biased
3. avalanched
4. saturated

✅ Correct Answer: 2

The term bias in electronics usually means ……….

1. the value of ac voltage in the signal.
2. the condition of current through a pn junction.
3. the value of dc voltages for the device to operate properly.
4. the status of the diode.

✅ Correct Answer: 3

Intrinsic semiconductors are those

1. Which are made of semiconductor material in its purest form
2. Which have zero energy gap
3. Which have more electrons than holes
4. Which are available locally

✅ Correct Answer: 1

Intrinsic semiconductor at room temperature will have, ................. available for conduction

1. Electrons
2. Holes
3. Both electrons and holes
4. none of the above

✅ Correct Answer: 3

A pure semiconductor behaves like an insulator at 00 K because

1. There is no recombination of electrons with holes
2. Drift velocity of free electrons is very small
3. Free electrons are not available for current conduction
4. Energy possessed by electrons at that low temperature is almost zero

✅ Correct Answer: 3

Which of the following is a semi-conductor

1. Diamond
2. Arsenic
3. Phosphorous
4. Gallium arsenide

✅ Correct Answer: 4

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

1. It has less number of electrons
2. It has high atomic mass number
3. Its crystal has much stronger bonds called ionic bonds
4. Its valence electrons are more tightly bound to their parent nuclii

✅ Correct Answer: 4

A semiconductor in its purest form is called.......

1. Insulator
2. Superconductor
3. Intrinsic semiconductor
4. Extrinsic semiconductor

✅ Correct Answer: 3

A P-type semiconductor results when

1. A pentavalent impurity is added to an intrinsic semiconductor
2. A trivalent impurity is added to an intrinsic semiconductor
3. Either a pentavalent or trivalent impurity is added to an intrinsic semiconductor
4. none of the above

✅ Correct Answer: 2

An intrinsic semiconductor at absolute zero.........

1. Becomes extrinsic semiconductor
2. Behaves like an insulator
3. Disintegrates into pieces
4. Becomes superconductor

✅ Correct Answer: 2

A semiconductor has.... temperature co-efficient of resistance.

1. Zero
2. Positive
3. Negative
4. none of the above

✅ Correct Answer: 3

A doped semiconductor is also known as

1. Intrinsic semiconductor
2. Extrinsic semiconductor
3. Diffused semiconductor
4. none of the above

✅ Correct Answer: 2

In semiconductor the forbidden energy gap lies

1. Just below the conduction band
2. Just above the conduction band
3. Either above or below the conduction band
4. Between the valence band and conduction band

✅ Correct Answer: 4

Which of the following cannot exist outside a semiconductor

1. Hole
2. Electron
3. Both (a) and (b)
4. none of the above

✅ Correct Answer: 1

In a N-type semiconductor, the positive of the Fermi level

1. Is at the centre of the energy gap
2. Is lower than the centre of energy gap
3. Is higher than the centre of energy gap
4. Can be anywhere depending upon the doping concentration

✅ Correct Answer: 3