A p-n photodiode is made of a material with a band gap of 2.0 eV. The minimum frequency of the radiation that can be absorbed by the material is nearly

1. $10\times {10}^{14} Hz$                             
2. $5\times {10}^{14} Hz$
3. $1\times {10}^{14} Hz$                               
4. $20\times {10}^{14} Hz$

The circuit is equivalent to

1. AND gate                              2. NAND gate

3. NOR gate                              4. OR gate 

In the forward bias arrangement of a PN-junction diode

(1) The N-end is connected to the positive terminal of the battery

(2) The P-end is connected to the positive terminal of the battery

(3) The direction of current is from N-end to P-end in the diode

(4) The P-end is connected to the negative terminal of battery

The cut-in voltage for silicon diode is approximately

(1) 0.2 V                       

(2) 0.6 V

(3) 1.1 V                       

(4) 1.4 V

The electrical circuit used to get smooth output from a rectifier circuit is called:

1. oscillator.

2. filter.

3. amplifier.

4. logic gates.

PN-junction diode works as a insulator, if connected

(1) To A.C.                             

(2) In forward bias

(3) In reverse bias                   

(4) None of these

The reverse biasing in a PN junction diode

1. Decreases the potential barrier

2. Increases the potential barrier

3. Increases the number of minority charge carriers

4. Increases the number of majority charge carriers

The electrical resistance of depletion layer is large because:

1. It has no charge carriers

2. It has a large number of charge carriers

3. It contains electrons as charge carriers

4. It has holes as charge carriers

In the circuit given below, the value of the current is

(1) 0 amp                         

(2) ${10}^{-2}$ amp

(3) ${10}^2$ amp                       

(4) ${10}^{-3}$amp