MCQ
$V$ (stopping potential) is plotted against $\frac{1}{\lambda}$, where $\lambda$ is wavelength of incident radiations, for two metals
  • A
    Metal $1$ may be gold and metal $2$ may be cesium
  • B
    $\theta_1 > \theta_2$, if metal $-1$ is gold and metal- $2$ is cesium
  • $\theta_1=\theta_2$, for any two metals
  • D
    $\theta_1 > \theta_2$, if metal $-1$ and metal- $2$ are gold and copper respectively

Answer

Correct option: C.
$\theta_1=\theta_2$, for any two metals
c
(c)

$\frac{h c}{\lambda}=\frac{h c}{632.2 \times 10^{-9}}$

$\frac{h c}{\lambda}=e V+w_0$

$e V=\frac{h c}{\lambda}-w_0$

$V=\frac{h c}{e} \times \frac{1}{\lambda}-\frac{w_0}{e}$

$\tan \theta=\frac{h c}{e}=$ constant [Slope of $V$ vs $\frac{1}{\lambda}$ graph]

$\therefore \theta$ is same for all metals.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free