Question

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R
Assertion A: Photodiodes are preferably operated in reverse bias condition for light intensity measurement
Reason R: The current in the forward bias is more than the current in the reverse bias for a $p-n$ junction diode
In the light of the above statements, choose the correct answer from the options given below:

• A. A is true but $R$ is false
• B. Both $A$ and $R$ are true and $R$ is the correct explanation of $A$
• C. A is false but $R$ is true
• D. Both $A$ and $R$ are true but $R$ is $N O T$ the correct explanation of $A$

Answer 1

The Correct Option is B

Photodiodes are operated in reverse bias because the fractional change in current due to light is easier to detect in reverse bias. While it is true that the forward bias current is greater than the reverse bias current, this is not the reason photodiodes are used in reverse bias.
Thus, \(A\) is true, and \(R\) is also true, but \(R\) is not the correct explanation for \(A\).