Question
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
-
2.4 V
-
-1.2 V
-
-2.4 V
-
1.2 V
Solution
D.
1.2 V
Energy of incident light E (eV) = 12375/2000 = 6.2 eV (200 nm = 2000 A)
According to the relation E = Wo +eVo
