Question
Question: Photoelectric emission is observed from a surface for frequencies n<sub>1</sub> and n<sub>2</sub> of...
Photoelectric emission is observed from a surface for frequencies n1 and n2 of incident radiations
(n1>n2). If the maximum K.E. of photoelectrons in two cases are in the ratio of 2 : 1, then threshold frequency n0 is given by -
A
2ν2−ν1
B
(2−1)2ν1−ν2
C
(2−1)2ν2−ν1
D
ν2−ν1
Answer
(2−1)2ν2−ν1
Explanation
Solution
K.E1 = hn1 – hn0
K.E2 = hn2 – hn0
Ž 12=hν2−hν0hν1−ν0
Ž 2 hn2 – 2hn0 = hn1 – hn0
Ž n0 = 12ν2−ν1