Assertion : Photosensitivity of a metal is high if its work function is small.
Reason : Work function `= hf_(0)` where `f_(0)` is the threshold frequency.

Options

A. Both A and R are true and R is the correct explanation of A
B. Both A and R are true and R is NOT the correct explanation of A
C. A is true but R is false
D. A is false and R is true

Answer

B

Explanation

Work function is less means less energy is required to eject photoelectrons. So, if the work function is less photosensitivity is high. So the assertion is true. Work function is the minimum energy required to eject a photoelectron and Work function `= hf_(0)`, where `f_(0)` is threshold frequency. So reason is also true but it does not explain the assertion.