A freshly prepared cesium surface has threshold frequency

PHYSICS · Multi-part · A Level · Physics · Particles and radiation · Particles and radiation

Problem

\nu_0

. Monochromatic light of frequency

\nu=1.02\,\nu_0

is incident on it. (i) Show that the maximum kinetic energy

K_{\max}

of the emitted electrons is

0.02\,h\nu_0

. (ii) Calculate the stopping potential corresponding to this

K_{\max}

in terms of

h

\nu_0

and

e

. (iii) The incident intensity is increased four times while the frequency remains unchanged. Explain quantitatively whether

K_{\max}

and the stopping potential will be affected. (iv) The frequency of incident light is now doubled to

2\,\nu_0

. Obtain the new value of

K_{\max}

in terms of

h\nu_0

and comment on the relative increase compared to part (i).