The depletion layer in the \(\mathrm{p\text-n}\) junction region is caused by:

1.	the drift of holes.
2.	diffusion of charge carriers.
3.	migration of impurity ions.
4.	drift of electrons.

The combination of gates shown below is equivalent to:
                
1. AND gate
2. XOR gate
3. NOR gate
4. NAND gate

The given circuit has two ideal diodes connected as shown in the figure below. The current flowing through the resistance \(R_1\) will be:
     

In the energy band diagram of a material shown below, the open circles and filled circles denote holes and electrons respectively. The material is a/an: 
     

The output in the circuit shown in the figure taken across a capacitor is:

1.		2.
3.		4.

Logic gates \(X\) and \(Y\) have the truth tables shown below:

When the output of \(X\) is connected to the input of \(Y\), the resulting combination is equivalent to a single:
1. NOT gate
2. OR gate
3. NAND gate
4. AND gate

The LED:
1. is reverse-biased.
2. is forward-biased.
3. can be made of \(\mathrm{GaAs}\).
4. both (2) & (3) are correct.