The potential difference that must be applied to stop the fastest photoelectrons emitted by a nickel surface, having work function 5.01 eV, when ultraviolet light of 200 nm falls on it, must be:

Options

(a) 2.4 V
(b) – 1.2 V
(c) – 2.4 V
(d) 1.2 V

Correct Answer:

1.2 V

Explanation:

Kₘₐₓ = hc / – W = hc / λ – 5.01
= 12375 / λ(in Å) – 5.01
12375 / 2000 – 5.01 = 6.1875 – 5.01 = 1.17775
= 1.2 V