Question

The work functions of three metals $A, \, B$ and $C$ are $W_{A}, \, W_{B}$ and $W_{C}$ respectively. They are in decreasing order. The correct graph between kinetic energy and frequency $\nu$ of incident radiation is

• A.
• B.
• C.
• D.

Answer 1

Answer: (B)

Irrespective of the photosensitive material used, the slope of each line should be same, since slope $=\frac{h}{e}$
Since, $W_{A}>W_{B}>W_{C} \, \Rightarrow \, \, \left(\left(\nu\right)_{0}\right)_{A}>\left(\left(\nu\right)_{0}\right)_{B}>\left(\left(\nu\right)_{0}\right)_{C}.$
$\therefore \, \, $ a is not possible.
Options (iii) and (iv) are not possible, since the graphs are not parallel.