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

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

In a junction diode, the holes are due to

(1) Protons                               

(2) Neutrons
(3) Extra electrons                     

(4) Missing of electrons

The cause of the potential barrier in a P-N diode is

(1) Depletion of positive charges near the junction

(2) Concentration of positive charges near the junction

(3) Depletion of negative charges near the junction

(4) Concentration of positive and negative charges near the junction

Which of the following statements is not true

(1) The resistance of intrinsic semiconductors decrease with increase of temperature

(2) Doping pure with trivalent impurities give P-type semiconductors

(3) The majority carriers in N-type semiconductors are holes

(4) A PN-junction can act as a semiconductor diode

The dominant mechanisms for motion of charge carriers in forward and reverse biased silicon P-N junctions are

(1) Drift in forward bias, diffusion in reverse bias

(2) Diffusion in forward bias, drift in reverse bias

(3) Diffusion in both forward and reverse bias

(4) Drift in both forward and reverse bias

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