The maximum velocity of electrons emitted from a metal surface is v. What would be the maximum velocity if the frequency of incident lightis increased by a factor of 4?

Options

A. `2 V`
B. `gt 2 V`
C. `lt 2 V`
D. Between `2 V` and `4 V`

Answer

B

Explanation

`because E = W_(0) + (1)/(2) mv_(max)^(2) rArr v_(max) = sqrt(( 2 (hf - W_(0)))/(m))`
If frequency becomes `4f` then
`V' = sqrt(( 2 (h xx 4f - W_(0)))/(m)) = 2 sqrt((2(hf - (W_(0))/(4)))/(m))`
`rArr V' gt 2 V`