Electronic Devices - Semiconductors - Discussion

Discussion Forum : Semiconductors - General Questions (Q.No. 28)
28.
A silicon diode is forward-biased. You measure the voltage to ground from the anode at ________, and the voltage from the cathode to ground at ________.
0 V, 0.3 V
2.3 V, 1.6 V
1.6 V, 2.3 V
0.3 V, 0 V
Answer: Option
Explanation:

For silicon diodes, the built-in potential is approximately 0.7 V. Thus, if an external current is passed through the diode, about 0.7 V will be developed across the diode such that the P-doped region is positive with respect to the N-doped region and the diode is said to be "turned on" as it has a forward bias.

Therefore, 2.3 V - 1.6 V = 0.7 V. Hence the answer is correct.

Discussion:
8 comments Page 1 of 1.

JBM said:   7 years ago
For Germanium diode V.drop of 0.3v.

Rajavelu said:   8 years ago
Can anyone say the same for a Germanium?

Shiju said:   1 decade ago
Thank you bharat.

Brahma said:   1 decade ago
I did not understand it clearly. Could you please explain it clearly?

Er R K TRIPATHI said:   1 decade ago
Thank you bharat.

Ramu said:   1 decade ago
Thank you bharat.

Bharat said:   1 decade ago
Voltage from anode to ground is 2.3v and after diode it became 1.6v beacuse silicion diode drop 0.7v so ans B is right.
because no other option is avaliable here for 0.7v drop.
(1)

Shweta bhatt said:   1 decade ago
Why we measure voltage from anode at 2.3V and the voltage from cathode to ground at 1.6V ?

Secondly why diode do not allow to set a voltage across it more than 0.7V and for the same reason it is used to protect certain zero crossing detectors based on op amp circuit?

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