Question

7. If the positive terminal of the battery is connected to the anode of the diode, then it is known as a) Forward biased b) Reverse biased c) Equilibrium d) Schottky barrier

Answer 1

Answer:

By convention, forward biasing of diode is defined in such a way that the positive terminal of the battery is connected to the anode (p-type crystal) of the diode whereas the negative terminal of the battery is connected to the cathode (n-type crystal) of the diode.

Moreover when the diode is forward biased then the potential barrier in depletion layer decreases......!!

Answer 2

If the positive terminal of the dc source is connected to the cathode and the negative terminal is connected to the anode, the diode is called reverse biased.

• When the diode is reverse biased then the depletion region width increases, majority carriers move away from the junction and there is no flow of current due to majority carriers but there are thermally produced electron-hole pairs also.
• If these electrons and holes are generated in the vicinity of the junction then there is a flow of current. The negative voltage applied to the diode will tend to attract the holes thus generated and repel the electrons.
• At the same time, the positive voltage will attract the electrons towards the battery and repel the holes. This will cause the current to flow in the circuit. This current is usually very small (in terms of microamp to nanoamp).
• Since this current is due to minority carriers and these number of minority carriers are fixed at a given temperature, therefore, the current is almost constant known as reverse saturation current ICO.