A and B are the inputs for the given logic gate. The output Y will be:

1.		2.
3.		4.

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

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. \(0.16\)

The LED:

1. is reverse-biased.

2. is forward-biased.

3. can be made of GaAs.

4. both (2) & (3) are correct.

The barrier potential of a \(\mathrm{p\text{-}n}\) junction depends on: 

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)

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)