Semiconductors Question 3
Question 3 - 25 January - Shift 1
Given below are two statements: one is labeled as Assertion A and the other is labeled 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 $|V_z|> \pm V \geq|V_0|$ where $V_o$ is the threshold voltage and $V_z$ is the breakdown voltage. In the light of the above statements, choose the correct answer from the options given below
(1) Both $A$ and $R$ are true and $R$ is correct explanation $A$
(2) Both $A$ and $R$ are true but $R$ is NOT the correct explanation A
(3) A is false but $R$ is true
(4) $A$ is true but $R$ is false
Show Answer
Answer: (3)
Solution:
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 ( for $V \leq V_z$ ).
Hence Assertion if false but Reason is true
