First slide

Photoelectric effect and study of photoelectric effect

Question

The graph between $\frac{1}{λ}$ and stopping potential (V) of three metals having work functions $ϕ_{1}, ϕ_{2}$ and $ϕ_{3}$ in an experiment of photo-electric effect is plotted as shown in the figure. Which of the following statement(s) is/are correct? [Here $λ$ is the wavelength of the incident ray].

Moderate

A

Ratio of work functions $ϕ_{1} : ϕ_{2} : ϕ_{3} = 4 : 2 : 1$
B

Ratio of work functions $ϕ_{3} : ϕ_{2} : ϕ_{1} = 4 : 2 : 1$
C

The violet colour light can eject photoelectrons from metals 2 and 3.
D

tan $θ$ is directly proportional to hc/e, where h is Planck's constant and c is the speed of light

Solution

$\begin{array}{l} eV = \frac{hc}{λ} - ϕ \\ \Rightarrow V = \frac{hc}{eλ} - \frac{ϕ}{e} = (\frac{hc}{e}) (\frac{1}{λ}) - \frac{ϕ}{e} \\ ∴ Slope = \tan θ = \frac{hc}{e} \\ ϕ = \frac{hc}{λ} \\ ϕ_{1} : ϕ_{2} : ϕ_{3} = \frac{1}{λ_{1}} : \frac{1}{λ_{2}} : \frac{1}{λ_{3}} = 1 : 2 : 4 \end{array}$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App