Question

Given below are two statements ; one is labelled as Assertion $A$ and the other is labelled as Reason $R$
Assertion A: Photodiodes are used in forward bias usually for measuring the light intensity.
Reason R: For a p-n junction diode. at applied voltage $V$ the current in the forward bias is more than the current in the reverse bias for $\left|V_2\right|>\pm V \geq\left|V_0\right|$ where $V_0$ is the threshold voltage and $V _2$ is the breakdown voltage.
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. A is false but $R$ is true
• C. Both $A$ and $R$ are true but $R$ is NOT the correct explanation $A$
• D. Both $A$ and $R$ are true and $R$ is correct explanation $A$

Answer 1

Answer: (B)

Theory based
Photodiodes are operated in reverse bias condition.
For $P - N$ junction current in forward bias (for $V \geq V _0$ ) is always greater than current in reverse bias $\left(\right.$ for $V \leq V _{ Z }$ ) .
Hence Assertion if false but Reason is true