When P-n Junction Is Reverse Biased

When p-n junction is reverse biased

Explanation: When a p-n diode is reverse biased, its depletion region is widened. This is because the voltage at the cathode will be higher than at the anode. This has the effect of increasing or decreasing the effective resistance of the junction itself allowing or blocking current flow through the diode. 2.

When pn junction diode is called reverse biased?

Hint: A p-n junction is said to be in reverse bias if the p-side of the junction is connected to a negative terminal of a battery and the n side is connected to the negative side of the battery.

When PN junction is reverse biased its junction resistance?

The resistance of a reverse biased P−N junction diode is about 106ohm.

Which of PN junction is forward biased Mcq?

The p-n Junction MCQ Question 8 Detailed Solution When the negative terminal of the battery is connected to the N - side and the positive terminal to P - side the connection is called forward bias.

What is a PN junction Mcq?

The interface or the boundary between the p-type and n-type semiconductor is called PN junction. The p-side has an excess of holes and n-type has an excess of electrons. Q1: In a PN junction with no external voltage, the electric field between acceptor and donor ion is called a. Peak.

What is reverse bias condition?

When we apply the external voltage across the semiconductor diode in such a way that the positive terminal of the battery is connected to its n-side and the negative terminal of the battery is connected to the p-side of the diode, then it is said to be in the condition of reverse bias.

What happens when PN junction is forward biased?

Solution : When a forward bias is applied to a p-n junction, the size of the depletion layer decreases. The resistance of the junction become low. The movement of the majority carriers takes place across the junction, resulting current, known as forward current which increase rapidly with increase in forward voltage.

When pn junction diode is reverse biased the width of the depletion layer?

The width of the depletion layer in a p-n junction diode increases in reverse bias as charge carriers are swept into battery terminals, holes from p-type into negative terminal and electrons from n-type into positive terminal.

Why there is high resistance in reverse bias?

<br> A large increase in reverse voltage across p-n junction shows small increase in reverse current. Hence the resistsnce of p-n junction is high when reverse biased.

Why does resistance increase in reverse bias?

Therefore the depletion layer widens, and does so increasingly with increasing reverse-bias voltage. This increases the voltage barrier causing a high resistance to the flow of charge carriers thus allowing only a very small electric current to leak across the PN junction.

Why forward bias has low resistance than the reverse bias?

Solution : In forward bias the thickness of depletion region decreases and barrier potential is lowered and consequently forward bias resistance is low as compared to the reverse bias condition in which depletion region broadened and barrier potential is raised.

Why it is called depletion region?

This region of uncovered positive and negative ions is called the depletion region due to the depletion of carriers in this region. The depletion region is so named because it is formed from a conducting region by removal of all free charge carriers, leaving none to carry a current.

Does a pn junction conduct in forward direction only?

A pn junction conducts only in forward biased condition.

What is reverse saturation current?

The reverse saturation current, also known as the saturation current (or scale current), is the portion of the reverse current in a semiconductor diode induced by minority carrier migration from the neutral to the depletion zones. The reverse voltage has essentially no effect on this current.

What is Zener voltage called?

Voltage regulator diodes actively use this characteristic. Since this breakdown voltage is also called Zener voltage, voltage regulator diodes are also called Zener diodes. This voltage may be used as a constant voltage power supply or a reference voltage for electronic circuits.

Why is PN junction used?

P-N junction diode can be used as a photodiode as the diode is sensitive to the light when the configuration of the diode is reverse-biased. It can be used as a solar cell. When the diode is forward-biased, it can be used in LED lighting applications.

What is another name for PN Crystal?

A PN crystal is commonly known as junction diode.

How do you reverse bias a diode?

Now, for a diode to be reverse-biased, the external bias voltage must be connected opposite of how it was connected to a diode in forward bias condition. So the positive side is connected to the n region while the negative side is connected to the p region.

Why current does not flow in reverse bias?

Whereas in reverse biasing, the depletion width at the p-n junction is thicker than that in forward biasing and its potential barrier is large. Thus the charge carriers cannot move across the depletion region and hence diode does not conduct electric current in reverse biasing.

What happens to a PN junction during both forward and reverse bias?

A forward bias diminishes the potential barrier, thus allowing current to flow effortlessly across the junction. In contrast, a reverse bias reinforces the potential barrier and impedes the flow of charge carriers.

11 When p-n junction is reverse biased Images