In the circuit shown in the diagram given below, R is a small resistor, Vi is the input voltage between A & B while Vis the output voltage between C & D.

Consider the following two statements and mark the correct option.
(I) If Vi > 2 V, then Vo = Vi
(II) If Vi < 2 V, then Vo = 2 V
1. I is true.
2. II is true.
3. I and II are both true.
4. I and II are both false.
Subtopic: Â PN junction |
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The dynamic resistance of a diode is given by $$R=\frac{26}{i(mA)}~\Omega,$$ where $$i$$ is the diode current.
 Statement I: If the current through the diode increases, then the dynamic resistance decreases. Statement II: If the temperature of the diode is increased, with the potential difference fixed, the dynamic resistance decreases.
 1 Statement I is incorrect and Statement II is correct. 2 Both Statement I and Statement II are correct. 3 Both Statement I and Statement II are incorrect. 4 Statement I is correct and Statement II is incorrect.
Subtopic: Â PN junction |
Â 68%
From NCERT
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The barrier potential of a $$\mathrm{p\text{-}n}$$ junction depends on:

 (a) type of semiconductor material (b) amount of doping (c) temperature

Which one of the following is correct?
1. (a) and (b) only
2. (b) only
3. (b) and (c) only
4. (a), (b) and (c)

Subtopic: Â PN junction |
Â 83%
From NCERT
NEET - 2014
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In the following figure, the diodes which are forward biased are:

 (a) (b) (c) (d)

1. (a), (b) and (d)
2. (c) only
3. (a) and (c)
4. (b) and (d)

Subtopic: Â PN junction |
Â 83%
From NCERT
AIPMT - 2011
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In an unbiased $p$-$n$ junction diode

1. p-type side is at higher potential than n-type side

2. p-type side is at lower potential than n-type side

3. Electric field is directed from $n$ side to $p$ side

4. Both 2 & 3

Subtopic: Â PN junction |
Â 59%
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The $$(I-V)$$ characteristics of a $$p-n$$ junction diode is as shown. If $$R_1$$ and $$R_2$$ be the dynamic resistance of the   $$p-n$$ junction when (i) a forward bias of $$1$$ volt is applied and (ii) a forward bias of $$2$$ volts is applied respectively, then $$\frac{R_1}{R_2}=?$$

1. $$160$$
2. $$16$$
3. $$1.6$$
4. $$0.16$$

Subtopic: Â PN junction |
Â 71%
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The voltage $$V_{AB}=20~V$$ at its peak value, and is sinusoidal in time. The current $$i$$ (in amperes), when plotted as a function of time, is given by:
(Consider the diodes as ideal.)
 1 2 3 4

Subtopic: Â PN junction |
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The current-voltage characteristic of an ideal $$\mathrm{p \text{-}n}$$ junction diode is given by the graph as shown in the following figure:

This diode is connected with a resistance of $$5~\Omega$$ in series with it as shown below:

Which of the following shows the dependence of the voltage $$V_{AB}$$ and the current $$i$$, when the diode is forward-biased? ($$V_{AB}$$ in volt, $$i$$ in ampere)

 1 $$V_{A B}=i\cdot5+0.6$$ 2 $$V_{A B}=i\cdot5-0.6$$ 3 $$V_{A B}=i\cdot5+(0.6-5)$$ 4 $$V_{A B}=i\cdot5+\left(0.6+5\right)$$
Subtopic: Â PN junction |
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