When 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

(1) $V_{\mathit{B}}$ increases, x decreases

(2) $V_{\mathit{B}}$ decreases, x increases

(3) $V_{\mathit{B}}$ increases, x increases

(4) $V_{\mathit{B}}$ decreases, x decreases

Function of rectifier is 

(1) To convert ac into dc             

(2) To convert dc into ac

(3) Both (a) and (b)                   

(4) None of these

When the P end of P-N junction is connected to the negative terminal of the battery and the N end to the positive terminal of the battery, then the P-N junction behaves like 

(1) A conductor                       

(2) An insulator

(3) A super-conductor             

(4) A semi-conductor

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 
1. $1.0\times {10}^6 \mathrm{V}/\mathrm{m}$                     

2. $1.0\times {10}^5 \mathrm{V}/\mathrm{m}$

3. $2.0\times {10}^5 \mathrm{V}/\mathrm{m}$                     

4. $2.0\times {10}^6 \mathrm{V}/\mathrm{m}$

If no external voltage is applied across P-N junction, there would be 

(1) No electric field across the junction

(2) An electric field pointing from N-type to P-type side across the junction

(3) An electric field pointing from P-type to N-type side across the junction

(4) A temporary electric field during formation of P-N junction that would subsequently disappear

Barrier potential of a P-N junction diode does not depend on 

(1) Temperature               

(2) Forward bias

(3) Doping density             

(4) Diode design (shape and size)

Which is the correct diagram of a half-wave rectifier?

1. 

2. 

3. 

4. 

The diode shown in the circuit is a silicon diode. The potential difference between the points A and B will be

(1) 6 V

(2) 0.6 V

(3) 0.7 V

(4) 0 V

Zener breakdown takes place if 

(1) Doped impurity is low             

(2) Doped impurity is high

(3) Less impurity in N-part           

(4) Less impurity in P-type

The correct symbol for zener diode is:

1.		2.
3.		4.