Photons with energy `5 eV` are incident on a cathode `C` in a photoelectric cell . The maximum energy of emitted photoelectrons is `2 eV`. When photons of energy `6 eV` are incident on `C` , no photoelectrons will reach the anode `A` , if the stopping potential of `A` relative to `C` is

Options

A. `-1 V`
B. `-3 V`
C. `+3 V`
D. `+4 V`

Answer

3

Explanation

`eV_(s)=(1)/(2)mv_(max)2=hv-phi_(0)`
`2=5--phi_(0)=3eV`
In second case `therefore V_(AC) =-3v`