The graph shows variation of stopping potential V₀ with the frequency u of the incident radiation for three photosensitive metals X₁, X₂ and X₃. Which metal will give out electrons with greater kinetic energy, for the same wavelength of incident radiation?

Question

The graph shows variation of stopping potential V₀ with the frequency 
u of the incident radiation for three photosensitive metals X₁, X₂ and X₃. Which metal will give out electrons with greater kinetic energy, for the same wavelength of incident radiation?

Accepted Answer

(1) X₁. Given: three parallel lines cutting the 
u axis at 1.0, 1.5 and 2×10¹⁴ Hz. Idea: eV₀=h
u-φ, so every line has the same slope h/e and its intercept on the 
u axis is the threshold frequency 
u₀=φ/h. X₁ has the smallest 
u₀, hence the smallest work function. For one incident frequency, Kₘₐₓ=h
u-φ is largest where φ is smallest. So X₁ gives the most energetic photoelectrons.

The graph shows variation of stopping potential V₀ with the frequency u of the incident radiation for three photosensitive metals X₁, X₂ and X₃. Which metal will give out electrons with greater kinetic energy, for the same wavelength of incident radiation?

Step-by-step solution

Why the other options are wrong