The frequency of incident light falling on a photosensitive metal plate is doubled, the K.E of the emitted photo-electrons is

Options

A. same as its initial value
B. two times its initial value
C. more than two times its initial value
D. less than two times its initial value

Answer

C

Explanation

`hv=W_(0)+1/2mv^(2)` or K.E. `(E_(1))=hv-W_(0)`
where `W_(0)` is the work function.
When v is doubled, `E_(2)=2hc-W_(0)` ...(1)
But `2E_(1)=2hv-2W_(0)` ...(2)
`:.E_(2) gt2E_(1)` (`:'W_(0)` will not change .)