Advertisements
Advertisements
Questions
Write the two processes that take place in the formation of a p-n junction.
Name two important processes involved in the formation of a p-n junction diode.
Advertisements
Solution
The processes of "diffusion" and "drift" are critical in a p-n junction. When the p and n-sides come into contact, the majority of carriers "diffuse" from a high concentration to a low concentration. Electrons move and combine with holes from the n-side to the p-side. Holes migrate from the p-side to the n-side in the same way that electrons and holes do at the junction. A "depletion region" is formed when the near junction area runs out of carriers and becomes charged. Current "diffusion" is caused by current "diffusion."
In the depletion area, the charge produces an electric field. The electric field creates a flow of minority carriers in the 'depletion' region. The produced current is known as "drift current," and it is referred to as drift. The directions of "diffusion and drift current" are reversed.
APPEARS IN
RELATED QUESTIONS
Explain, with the help of a circuit diagram, the working of n-p-n transistor as a common emitter amplifier.
When a p-n junction is reverse-biased, the current becomes almost constant at 25 µA. When it is forward-biased at 200 mV, a current of 75 µA is obtained. Find the magnitude of diffusion current when the diode is
(a) unbiased,
(b) reverse-biased at 200 mV and
(c) forward-biased at 200 mV.
Calculate the current through the circuit and the potential difference across the diode shown in figure. The drift current for the diode is 20 µA.

Find the equivalent resistance of the network shown in figure between the points A and B.

(Assume that the resistance of each diode is zero in forward bias and is infinity in reverse bias.)
A load resistor of 2kΩ is connected in the collector branch of an amplifier circuit using a transistor in common-emitter mode. The current gain β = 50. The input resistance of the transistor is 0.50 kΩ. If the input current is changed by 50µA. (a) by what amount does the output voltage change, (b) by what amount does the input voltage change and (c) what is the power gain?
Answer in detail.
Discuss the effect of external voltage on the width of depletion region of a p-n junction.
The depletion layer in the p-n junction diode is caused by ______.
In a semiconductor diode, the barrier potential offers opposition to only ______.
Zener breakdown occurs in a p-n junction having p and n both:
In p-n junction diode ______.
