Question

While conducting a photoelectric-effect experiment with light of a certain

frequency, you find that a reverse potential difference of 1.25 V is required

to reduce the current to zero. Find (a) the maximum kinetic energy and (b)

the maximum speed of the emitted photoelectrons.

Answer 1

(a) $KE=eV=1.25\text{ eV}.$

(b) $v=\sqrt{2KE/m}=663.1\text{ km/s}.$