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

The PN junction diode is used as

(1) An amplifier                       

(2) A rectifier

(3) An oscillator                       

(4) A modulator

In the depletion region of an unbiased P-N junction diode there are

(1) Only electrons

(2) Only holes

(3) Both electrons and holes

(4) Only fixed ions

On increasing the reverse bias to a large value in a PN-junction diode, current

1. Increases slowly                 

2. Remains fixed

3. Suddenly increases             

4. Decreases slowly

In the case of forward biasing of PN-junction, which one of the following figures correctly depicts the direction of flow of carriers

A semiconductor device is connected in a series circuit with a battery and a resistance. A current is found to pass through the circuit. If the polarity of the battery is reversed, the current drops almost to zero. The device may be

(1) A P-type semiconductor               

(2) An N-type semiconductor

(3) A PN-junction                               

(4) An intrinsic semiconductor

The approximate ratio of resistances in the forward and reverse bias of the P-N junction diode is:

(a) ${10}^2:1$                     (b) ${10}^{-2}:1$
(c) $1:{10}^{-4}$                   (d) $1:{10}^4$ 

In a junction diode, the holes are due to

(1) Protons                               

(2) Neutrons

(3) Extra electrons                     

(4) Missing of electrons

In forward bias, the width of potential barrier in a P-N junction diode 

(1) Increases

(2) Decreases

(3) Remains constant

(4) First increases then decreases