Question

Part B 
In another experiment, the intensity of the incident light and the temperature of the metal are held constant. Assuming that the initial light incident on the metal surface causes electrons to be ejected from the metal, what happens if the frequency of the incident light is increased?

Check all that apply.
   The work function of the metal increases.
   The number of electrons emitted from the metal per second increases.
   The maximum speed of the emitted electrons increases.
   The stopping potential increases.

Answer 1

In photo electric effect, Electron \(\mathrm{KE}=\) photon energy - work function. \(\frac{1}{2} m v^{2}=h f-\phi\)

and

Stopping potential \(=\frac{\mathrm{KE}}{\text { electronic charge }}\)

Therefore, increasing frequency \(f\) then, increasing photon energy \(\Rightarrow\) increasing \(\mathrm{KE}\) enegy \(\Rightarrow\) increasing electron speed \(\mathrm{v}\) and stopping potential.

Hence the answers are

The maximum speed of the emitted electrons increases.

The stopping potential increases.