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

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

In a PN-junction diode not connected to any circuit

(1) The potential is the same everywhere

(2) The P-type is at higher potential than the N-type side

(3) There is an electric field at the junction directed from the N- type side to the P- type side

(4) There is an electric field at the junction directed from the P-type side to the N-type side

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

Which one is reverse-biased