Which one is in forward bias

The reason of current flow in P-N junction in forward bias is

(1) Drifting of charge carriers

(2) Minority charge carriers

(3) Diffusion of charge carriers

(4) All of these

The resistance of a reverse biased P-N junction diode is about 
(1) 1 ohm                       

(2) ${10}^2$ohm

(3) ${10}^3$ ohm                     

(4) ${10}^6$ ohm

Avalanche breakdown is due to 

(1) Collision of minority charge carrier

(2) Increase in depletion layer thickness

(3) Decrease in depletion layer thickness

(4) None of these

Zener breakdown in a semi-conductor diode occurs when

(1) Forward current exceeds certain value

(2) Reverse bias exceeds certain value

(3) Forward bias exceeds certain value

(4) Potential barrier is reduced to zero

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