Question
Question: Photoelectron are emitted with maximum kinetic energy E from a metal surface when light of frequency...
Photoelectron are emitted with maximum kinetic energy E from a metal surface when light of frequency υ falls on it when light of frequency υ' falls on the same metal, the max. KE. Of emitted Photoelectrons is found to be 2E then υ' is –
A
υ1 = υ
B
υ1 = 2υ
C
υ1> 2υ
D
υ1< 2υ
Answer
υ1> 2υ
Explanation
Solution
KE = hυ + φ …..(i)
2KE = hυ' + φ ……(ii)
or 2 (hυ + φ) = hυ' + φ
or υ' = 2υ + ⇒ υ' > 2υ