Physics 9702 · AS & A Level · Photoelectric effect

Photoelectric effect — practice question

(a)[2]

State what the threshold frequency means, with reference to the photoelectric effect.

(b(i))[2]

Electromagnetic radiation with wavelength $\lambda$ falls on a metal surface, and electrons with maximum kinetic energy $E_{\text{MAX}}$ are produced. On Fig. 11.1, sketch how $E_{\text{MAX}}$ varies with $\frac{1}{\lambda}$.

(b(ii))[1]

State an equation linking the gradient of the graph in Fig. 11.1 to the Planck constant $h$. Explain any symbols you use.

(b(iii))[2]

Explain why, for a given wavelength of electromagnetic radiation, most emitted electrons have kinetic energies below the maximum value $E_{\text{MAX}}$.

(b)

Electromagnetic radiation with wavelength $\lambda$ falls on a metal surface, and electrons with maximum kinetic energy $E_{\text{MAX}}$ are produced.

(b(iv))[3]

Light of one wavelength shines on a metal surface and produces a photoelectric current. The wavelength is reduced while the light intensity remains constant. State and explain, if there is any, the change in the photoelectric current.

Worked solution & mark scheme

This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: Lowest frequency needed to release electrons from a metal surface

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