Which expression gives the maximum kinetic energy of an electron emitted from a metal…

PHYSICS · Single correct · A Level · Physics · Particles and radiation · Particles and radiation

Problem

Which expression gives the maximum kinetic energy

K_{\text{max}}

of an electron emitted from a metal surface when it is illuminated by monochromatic light of frequency

f

and the metal has work function

\phi

? (a)

K_{\text{max}} = hf + \phi

(b)

K_{\text{max}} = hf - \phi

(c)

K_{\text{max}} = hf

(d)

K_{\text{max}} = \dfrac{hf-\phi}{2}