The energy band diagrams for semiconductor samples of silicon are as shown. We can assert that:

          

1.	sample X is undoped while samples Y and Z have been doped with a third group and a fifth group impurity respectively.
2.	sample X is undoped while both samples Y and Z have been doped with a fifth group impurity.
3.	sample X has been doped with equal amounts of third and fifth group impurities while samples Y and Z are undoped.
4.	sample X is undoped while samples Y and Z have been doped with a fifth group and a third group impurity respectively.

An LED is constructed from a \(\mathrm{p\text{-}n}\) junction diode using \(\mathrm{GaAsP}\). The energy gap is \(1.9~\text{eV}\). The wavelength of the light emitted will be equal to:
1. \(10.4 \times 10^{-26} \text{m}\)
2. \(654~ \text{nm}\)
3. \(654~ \text{m}\)
4. \(654\times 10^{-11}~\text{m}\)

A potential barrier of 0.50 V exists across a p-n junction. If the depletion region is $5.0\times {10}^{-7}$ m wide, the intensity of the electric field in this region is:

If the reverse bias in a junction diode is changed from \(5\) V to \(15\) V then the value of current changes from \(38\) \(\mu \text{A}\) to \(88\) \(\mu \text{A}.\) The resistance of junction diode will be:
1. \(4\times10^{5}\) 
2. \(3\times10^{5}\)
3. \(2\times10^{5}\)
4. \(10^{6}\)

The current through an ideal p-n junction diode shown in the circuit will be:

1.  5 A

2.  0.2 A 

3.  0.6 A

4.  Zero

Which logic gate is represented by the following combination of logic gates?
   
1. OR

2. NAND

3. AND

4. NOR

In a p-n junction diode not connected to any circuit:

When a forward bias is applied to a p-n junction, then what happens to the potential barrier $V_{\mathit{B}}$, and the width of charge depleted region x?

Which of the energy band diagrams shown in the figure corresponds to that of a semiconductor?

1.		2.
3.		4.

In a given circuit as shown the two input waveforms A and B are applied simultaneously. The resultant waveform Y is:

1.		2.
3.		4.