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.

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

1.		2.
3.		4.

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

In a half-wave rectification, what is the output frequency if the input frequency is \(50\) Hz?

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 given circuit has two ideal diodes connected as shown in the figure below. The current flowing through the resistance R₁ will be:
     

The depletion layer in the P–N junction region is caused by:

The LED:

1. is reverse-biased.

2. is forward-biased.

3. can be made of GaAs.

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