# JEE Main

Explore popular questions from Electronic Devices & Semiconductor for JEE Main. This collection covers Electronic Devices & Semiconductor previous year JEE Main questions hand picked by experienced teachers.

## Mathematics

Electronic Devices & Semiconductor

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Q 1. If the lattice constant of this semiconductor is decreased, then which of the following is correct?

A

all {tex} E _ { c } , E _ { g } , E _ { v } {/tex} decrease

B

all {tex} E _ { c } , E _ { g } , E _ { v } {/tex} increase

C

{tex} E _ { c } , {/tex} and {tex} E _ { v } {/tex} increase, but {tex} E _ { g } {/tex} decreases

{tex} E _ { c } , {/tex} and {tex} E _ { v } {/tex} decrease, but {tex} E _ { g } {/tex} increases.

##### Explanation

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Q 2. At absolute zero, Si acts as

A

non-metal

B

metal

insulator

D

none of these.

##### Explanation

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Q 3. By increasing the temperature, the specific resistance of a conductor and a semiconductor

A

increases for both

B

decreases for both

increases, decreases

D

decreases, increases.

##### Explanation

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Q 4. The energy band gap is maximum in

A

metals

B

superconductors

insulators

D

semiconductors.

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Q 5. The part of a transistor which is most heavily doped to produce large number of majority carriers is

emitter

B

base

C

collector

D

can be any of the above three.

##### Explanation

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Q 6. Formation of covalent bonds in compounds exhibits

wave nature of electron

B

particle nature of electron

C

both wave and particle nature of electron

D

none of these.

##### Explanation

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Q 7. The difference in the variation of resistance with temperature in a metal and a semiconductor arises essentially due to the difference in the

A

crystal structure

variation of the number of charge carriers with temperature

C

type of bonding

D

variation of scattering mechanism with temperature.

##### Explanation

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Q 8. For a transistor amplifier in common emitter configuration for load impedance of {tex} 1 \mathrm { k } \Omega {/tex} {tex} \left( h _ { f e } = 50 \text { and } h _ { o e } = 25 \right) {/tex} the current gain is

A

{tex} - 5.2 {/tex}

B

{tex} - 15.7 {/tex}

C

{tex} - 24.8 {/tex}

{tex} - 48.78 {/tex}

##### Explanation

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Q 9. A n-type semiconductor is

A

negatively charged

B

positively charged

neutral

D

none of these

##### Explanation

n-type semiconductors are neutral because neutral atoms are added during doping

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Q 10. The manifestation of band structure in solids is due to

A

Heisenberg's uncertainty principle

Pauli's exclusion principle

C

Bohr's correspondence principle

D

Boltzmann's law

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Q 11. When {tex} p - n {/tex} junction diode is forward biased, then

A

the depletion region is reduced and barrier height is increased

B

the depletion region is widened and barrier height is reduced.

both the depletion region and barrier height are reduced

D

both the depletion region and barrier height are increased