Olete.in – MCQs, Mock Tests & Government Job Prep | Semiconductor Semiconductor Mcq Question Set 2

As the temperature of a semiconductor increases its

1. Conductivity increases
2. Resistivity increases
3. Atomic number decreases
4. Temperature co-efficient becomes zero

✅ Correct Answer: 1

Which of the following doping elements would not be suitable for converting intrinsic semiconductor

1. Phosphorous
2. Indium
3. Antimony
4. Arsenic

✅ Correct Answer: 2

The forward region of a semiconductor diobe characteristic curve is where diode appears as

1. High resistance
2. An ON switch
3. An OFF switch
4. A capacitor

✅ Correct Answer: 2

In a semiconductor diode, the barrier offers opposition to

1. Majority carriers in both regions
2. Majority as well as minority carriers in both regions
3. all of the above
4. None of the mentioned

✅ Correct Answer: 1

In case of semiconductors, recombination is merging of

1. An electrons with a hole
2. An outside electron with semiconductor electrons
3. Two or more electrons
4. Two or more holes

✅ Correct Answer: 2

The conduction band

1. Is always above the forbidden energy level
2. Is the region of free electrons
3. Concentrates holes for the flow of current
4. Is a range of energies corresponding to the energies of the free electrons

✅ Correct Answer: 4

The temperature co-efficient of an intrinsic semiconductor is.......

1. Zero
2. Positive
3. Negative
4. None of them

✅ Correct Answer: 3

The temperature co-efficient of an extrinsic semiconductor is.......

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

✅ Correct Answer: 3

....... has the highest mobility.

1. Electron
2. Positive ions
3. Negative ions
4. Neutron

✅ Correct Answer: 1

At room temperature N-type material will have....

1. More of electrons
2. More of holes
3. Equal number of electrons and holes
4. None of the mentioned

✅ Correct Answer: 1

A room temperature P-type material will have....

1. More of electrons
2. More of holes
3. Equal number of electrons and holes
4. None of the mentioned

✅ Correct Answer: 2

Nucleus is made of

1. Electrons and protons
2. Photons and neutrons
3. Photons and neutrons
4. Photons and electrons

✅ Correct Answer: 4

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

1. Valence band
2. Forbidden band or
3. Conduction band or
4. It can be at any of the above locations depending upon the doping concentration and temperature

✅ Correct Answer: 2

In any specimen the Hall voltage is proportional to magnetic field β as

1. β
2. β2
3. 1/β
4. 1/β2

✅ Correct Answer: 2

Intrinsic concentration of charge carriers in a semiconductor varies as

1. T3
2. T2
3. T
4. 1/T

✅ Correct Answer: 1

The dynamic resistance of a diode varies as

1. I the current
2. I2
3. 1/I
4. 1/I2

✅ Correct Answer: 3

The forbidden band in germanium at 00K is

1. 0.03 eV
2. 0.785 eV
3. 1.5 eV
4. 2.0 eV

✅ Correct Answer: 2

The atomic number of germanium is.......

1. 4
2. 8
3. 16
4. 32

✅ Correct Answer: 4

Which of the following elements belog to the same group of periodic tables as that of silicon and germanium

1. Phosphorous
2. Carbon
3. Sodium
4. Boron

✅ Correct Answer: 2

.... is used to describe the static V/I characteristic of a junction diode

1. Bolzmann diode equation
2. Richardson-Dushman equation
3. Child's Three half-power law
4. Einstein's photoelectric equation

✅ Correct Answer: 1

Acceptor-type impurities

1. Can be added to silicon but not to germanium
2. Create excess electrons
3. Must have three velence electrons
4. Must have five valence electrons

✅ Correct Answer: 3

The movement of a hole results from.......

1. Excitation due to high temperature
2. Change in number of protons in the atom
3. The vacancy filled by a valence electron from the neighbouring atom
4. None of above

✅ Correct Answer: 3

For a germanium P-N junction, the barrier potential is nearly.......

1. 0.15 V
2. 0.3 V
3. 0.45 V
4. 0.6 V/span>

✅ Correct Answer: 2

For a silicon P-N junction, the barrier potential is about

1. 0.7 V
2. 0.8 V
3. 0.9 V
4. 1.0 V

✅ Correct Answer: 1

In order to obtain a P-type germanium, the germanium should be doped with a ........ impurity

1. Trivalent
2. Tetravalent
3. Pentavalent
4. Any of the above

✅ Correct Answer: 1

...... are immobile.

1. Ions
2. Electrons
3. Holes
4. none of the above

✅ Correct Answer: 1

A zener diode is invariably used with

1. Reverse bias
2. Forward bias
3. Zero bias
4. Any of the above

✅ Correct Answer: 1

The crystal diode is used as a

1. Rectifer
2. Amplifier
3. Oscillator
4. Any of the above

✅ Correct Answer: 1

Ripple factor is the ratio of ...value to ... value

1. r.m.s., peak
2. peak, D.C
3. r.m.s., D.C
4. peak, r.m.s

✅ Correct Answer: 3

Addition of impurity in the ratio of 1 in 10 to a pure or intrinsic semiconductor

1. Increases its conductivity nearly 10 times
2. Increases its conductivity nearly 100 times
3. Decreases its conductivity nearly 100 times
4. Increases its resistivity nearly 100 times

✅ Correct Answer: 4

With increases of reverse bias, the reverse saturation current in P-N diode

1. Increases
2. Remains constant
3. Increases
4. Increases as inverse of reverse bias

✅ Correct Answer: 2

The maximum reverse voltage that can be applied to an ordinary semiconductor diode without irreverslible damage is called .....

1. Cut-off voltage
2. Avalanche breakdown voltage
3. Peak inverse voltage
4. Zener voltage

✅ Correct Answer: 3

The resistivity of a semiconductor lies

1. Below 10-6
2. Between 10-6 to 102 ohm-metre
3. Between 10-6 to 104 ohm-metre
4. Above 104 ohm-metre

✅ Correct Answer: 2

Which of the following materials can be used to make a light-emitting diode?

1. Silicon
2. Germanium
3. Gallium arsenide
4. Phosphorescent material

✅ Correct Answer: 3

Which of the following is an active device?

1. Electric bulb
2. Transformer
3. SCR
4. Loudspeaker

✅ Correct Answer: 3

Which of the following is a passive component?

1. Vacumm tube devices
2. Capacitors
3. Semiconductor devices
4. All of the above

✅ Correct Answer: 2

For a half wave rectified sine wave the ripple factor is

1. 1.65
2. 1.45
3. 1.21
4. 1.00

✅ Correct Answer: 3

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. 6 × 104 Ω cm
2. 60 Ω cm
3. 3 × 106 Ω cm
4. 6 × 10−4 Ω cm

✅ Correct Answer: 2

The resistivity of pure silicon is about ……..

1. 100 Ω cm
2. 6000 Ω cm
3. 3 × 105 Ω cm
4. 1.6 × 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. cannot 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

A trivalent impurity has …….. valence electrons.

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

✅ Correct Answer: 4

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