Electronic Devices - Semiconductors - Discussion

@All.

According to me,

1. When the diode is forward biased, it acts like a closed switch. So, only a few/less resistance required to conduct it.

2. When the diode is reverse biased, it acts like an open switch. So, a high resistance (infinity) is required to conduct it (pass current through it).

3. Some say, this is internally short. (in both forward and reversed bias).

In ideal cases, the internal resistance (when short) can be zero.

But, in practical cases, the internal resistance (when short) cannot be zero. It offers at least a few resistance.

But, this case is not good for a diode.

Am I right? Please tell me.

Yes, it should not be internally shorted because according to me, the resistance can come to zero.

Good working Diode in Forward Bias acts as a closed switch therefore Forward Resistance is low.

In Reverse Bias, it acts as an open switch therefore Reverse Resistance is High.

If the diode has low resistance in both the cases then it is shorted internally and not good for use.

In forward bias a diode is short circuit and have zero resistance, so silicon diode measure a low value of resistance.

It is absolutely sure that ideal condition is absolutely different from the practical condition so we have to understand on the practical basis.

What is the meaning of 'trouble if any' in the question?

That moment diode is conducting. That means current flowing through the diode so resistance is Zero of that time.

Diode measures the low resistance means, diode should be in forward bias.

How the meter show 2 different values for measuring a single resistance?

As the diode conducts it shows no resistance.