Question

The graph between 1/$\lambda$ and stopping potential (V) of three metals having work functions ${\Phi }_1,{\Phi }_2\text{and}{\Phi }_3$ in anexperiment of photo-electric effect is plotted as shown in the figure.Which of the following statement(s) is correct? [Here $\lambda$ is the wavelength of the incident ray].

• A. Ratio of work functions ₁ :₂ : ₃ = 1 : 2 : 4
• B. Ratio of work functions ₁ :₂ : ₃ = 4 : 2 : 1
• C. tanθ is directly proportional to h/e, where h is Planck’s constant and c is the speed of light.
• D. The violet colour light can eject photoelectrons from metals 1 and 2.

Answer 1

The correct option is A

Ratio of work functions ₁ :₂ : ₃ = 1 : 2 : 4

$\Phi =\frac{hc}{{\lambda }_0}\Phi \alpha \frac{1}{{\lambda }_0}=x-\text{intercept}$