Semiconductor Electronics : Materials, Devices and Simple Circuits Easy Questions and Answers | Page - 19

Semiconductor Electronics : Materials, Devices and Simple Circuits

If a small amount of antimony is added to germanium crystal

1. it becomes a p–type semiconductor
1. the antimony becomes an acceptor atom
1. there will be more free electrons than holes in the semiconductor
1. its resistance is increased

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When small amount of antimony (pentavalent) is added to germanium crystal then crystal becomes n-type semi conductor. Therefore, there will be more free electrons than holes in the semiconductor.

Correct Option: C

When small amount of antimony (pentavalent) is added to germanium crystal then crystal becomes n-type semi conductor. Therefore, there will be more free electrons than holes in the semiconductor.

In forward biasing of the p–n junction

1. the positive terminal of the battery is connected to p–side and the depletion region becomes thick
1. the positive terminal of the battery is connected to n–side and the depletion region becomes thin
1. the positive terminal of the battery is connected to n–side and the depletion region becomes thick
1. the positive terminal of the battery is connected to p–side and the depletion region becomes thin

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In forward biasing of the p-n junction, the positive terminal of the battery is connected to p-side and the negative terminal of the battery is connected to n-side. The depletion region becomes thin.

Correct Option: D

In forward biasing of the p-n junction, the positive terminal of the battery is connected to p-side and the negative terminal of the battery is connected to n-side. The depletion region becomes thin.

C and Si both have same lattice structure, having 4 bonding electrons in each. However, C is insulator whereas Si is intrinsic semiconductor. This is because :

1. In case of C the valence band is not completely filled at absolute zero temperature.
1. In case of C the conduction band is partly filled even at absolute zero temperature.
1. The four bonding electrons in the case of C lie in the second orbit, whereas in the case of Si they lie in the third.
1. The four bonding electrons in the case of C lie in the third orbit, whereas for Si they lie in the fourth orbit.

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Electronic configuration of ⁶C
⁶C = 1s², 2s² 2p²
The electronic configuration of ¹⁴Si
¹⁴Si = 1s², 2s² 2p⁶, 3s² 3p²
As they are away from Nucleus, so effect of nucleus is low for Si even for Sn and Pb are almost mettalic.

Correct Option: C

Electronic configuration of ⁶C
⁶C = 1s², 2s² 2p²
The electronic configuration of ¹⁴Si
¹⁴Si = 1s², 2s² 2p⁶, 3s² 3p²
As they are away from Nucleus, so effect of nucleus is low for Si even for Sn and Pb are almost mettalic.

Two ideal diodes are connected to a battery as shown in the circuit. The current supplied by the battery is :

1. 0.75 A
1. zero
1. 0.25 A
1. 0.5 A

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Here D₁ is in forward bias and D₂ is in reverse bias so, D₁ will conduct and D₂ will not conduct. Thus, no current will flow through DC.
I = ΔV = 5 = 1 Amp.
R 10 2

Correct Option: D

Here D₁ is in forward bias and D₂ is in reverse bias so, D₁ will conduct and D₂ will not conduct. Thus, no current will flow through DC.
I = ΔV = 5 = 1 Amp.
R 10 2

In an unbiased p-n junction, holes diffuse from the p-region to n-region because of

1. the potential difference across the p-n junction
1. the attraction of free electrons of n-region
1. the higher hole concentration in p-region than that in n-region
1. the higher concentration of electrons in the n-region than that in the p-region

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In p-region of p-n junction holes concentration > electrons concentration and in n-region electrons concentration > holes concentration.

Correct Option: C

In p-region of p-n junction holes concentration > electrons concentration and in n-region electrons concentration > holes concentration.