Identify the incorrect statement from the following:

1.	The resistivity of a semiconductor increases with an increase in temperature.
2.	Substances with an energy gap of the order of 10 eV are insulators.
3.	In conductors, the valence and conduction bands may overlap.
4.	The conductivity of a semiconductor increases with an increase in temperature.

Application of a forward bias to a p-n junction:

Of the diodes shown in the following diagrams, which one of the diodes is reverse biased?
 

1.		2.
3.		4.

The truth table for the following network is:

In semiconductors at room temperature:

In a p–n junction photocell, the value of the photo electromotive force produced by monochromatic light is proportional to:

For the given circuit of the P-N junction diode, which of the following statements is correct?

Reverse-bias applied to a junction diode:

The barrier potential of a p-n junction diode does not depend on:

1. diode design

2. temperature

3. forward bias

4. doping density

Following diagram performs the logic function of:

1. AND gate

2. NAND gate

3. OR gate

4. XOR gate