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10 months ago

Physics Semiconductor Electronics

The output of the given circuit in figure is given below.

(a) Would be zero at all times

(b) Would be like a half wave rectifier with positive cycles in output
(c) Would be like a half wave rectifier with negative cycles in output
(d) Would be like that of a full wave rectifier

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alok kumar singh

Contributor-Level 10

This is a Multiple Choice Questions as classified in NCERT Exemplar

Answer- c

Explanation- due to forward biasing the diffusion current in the circuit is very high and resistance in the circuit is very low. Thus voltage across pn junction is very low but in case of reverse biasing diffusion current very small so resistance becomes very high . and that end making high voltage across pn junction.

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10 months ago

Physics Semiconductor Electronics

Hole is
(a) An anti-particle of electron
(b) A vacancy created when an electron leaves a covalent bond
(c) Absence of free electrons
(d) An artificially created particle

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alok kumar singh

Contributor-Level 10

This is a Multiple Choice Questions as classified in NCERT Exemplar

Answer-b

Explanation -when a neutral entity is there it contains both equal number of elctron and holes. Also when electron emit from neutral entity then it leave behind a vacancy that is hole.

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New question posted

10 months ago

Physics Semiconductor Electronics

Hole is
(a) An anti-particle of electron
(b) A vacancy created when an electron leaves a covalent bond
(c) Absence of free electrons
(d) An artificially created particle

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New answer posted

10 months ago

Physics Semiconductor Electronics

A 220 V AC supply is connected between points A and B (figure). What will be the potential difference V across the capacitor?

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alok kumar singh

Contributor-Level 10

This is a Multiple Choice Questions as classified in NCERT Exemplar

Answer- d

Explanation- as we know that Ev = E_o/ $\sqrt[]{2}$ so E₀= Ev $\sqrt[]{2}$ so net voltage is 220 $\sqrt[]{2}$ V

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New answer posted

10 months ago

Physics Semiconductor Electronics

In figure given on next page, assuming the diodes to be ideal
(a) D₁is forward biased and D₂ is reverse biased and hence current flows from A to B
(b) D₂ is forward biased and D₁ is reverse biased and hence no current flows from B to A and vice-versa
(c) D₁ and D₂ are both forward biased and hence current flows from A to B
(d) D₁ and D₂ are both reverse biased and hence no current flows from A to B and vice-versa

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alok kumar singh

Contributor-Level 10

This is a Multiple Choice Questions as classified in NCERT Exemplar

Answer-b

Explanation- from the figure we can say that diode D1 is reverse biased and diode D2 is forward biased so current will flow from B to A.

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10 months ago

Physics Semiconductor Electronics

In figure given below V₀ is the potential barrier across a pn junction when no battery is connected across the junction

(a) 1 and 3 corresponds to forward bias of junction

(b) 3 corresponds to forward bias of junction and 1 corresponds to reverse bias of the junction

(c) 1 corresponds to forward bias and 3 corresponds to reverse bias of the junction

(d) 3 and 1 both corresponds to reverse bias of the junction

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alok kumar singh

Contributor-Level 10

This is a Multiple Choice Questions as classified in NCERT Exemplar

Explanation - When p-n junction is forward biased, it opposes the potential barrier junction, when p-n junction is reverse biased, it supports the potential barrier junction, resulting increase in potential barrier across the junction.

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10 months ago

Physics Semiconductor Electronics

The conductivity of a semiconductor increases with increase in temperature, because
(a) Number density of free current carries increases
(b) Relaxation time increases
(c) Both number density of carries and relaxation time increase
(d) Number density of carries increases, relaxation time decreases but effect of decrease in relaxation time is much less than increase in number density

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alok kumar singh

Contributor-Level 10

This is a Multiple Choice Questions as classified in NCERT Exemplar

Answer- (d)

Explanation- when we increase temperature conductivity increases because number density is increasing after increasing temperature which decreases the relaxation time

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New answer posted

10 months ago

Physics Semiconductor Electronics

A Zener of power rating 1 W is to be used as a voltage regulator. If Zener has a breakdown of 5 V and it has to regulate voltage which fluctuated between 3 V and 7 V, what should be the value of Rs for safe operation (see figure)?