Practice portal › Dual Nature of Matter and Radiation › Photoelectric Graphs

The slope of a graph of stopping potential versus frequency of incident radiation is ______. (where h = Planck's constant and e = charge of an electron)

Asked in GSEB Board July 2021 · Stopping potential and kinetic energy graphs

Figure: Stopping potential and kinetic energy graphs
Answer: (3) h/e

Step-by-step solution

Idea: Einstein's photoelectric equation eV₀ = h u - φ₀.

Divide by e: V₀ = (h/e) u - (φ₀)/e.

This has the form y = mx + c with y = V₀ and x = u.

So the slope is h/e (about 4.1×10⁻¹⁵ V s), the same for every metal; only the intercept changes from metal to metal.

Why the other options are wrong

More Photoelectric Graphs questionsAll Photoelectric Graphs questions →

Reading this solution needs no sign-in. You only sign in to practise against the clock and keep your progress.

Practise this with a timer