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)

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.

Which one of the following statements is not correct

(1) A diode does not obey Ohm's law

(2) A PN junction diode symbol shows an arrow identifying the direction of current (forward) flow

(3) An ideal diode is an open switch

(4) An ideal diode is an ideal one way conductor

A semiconductor X is made by doping a germanium crystal with arsenic (Z = 33). A second semiconductor Y is made by doping germanium with indium (Z = 49). The two are joined end to end and connected to a battery as shown. Which of the following statements is correct

(1) X is P-type, Y is N-type and the junction is forward biased

(2) X is N-type, Y is P-type and the junction is forward biased

(3) X is P-type, Y is N-type and the junction is reverse biased

(4) X is N-type, Y is P-type and the junction is reverse biased