The electric field associated with a light wave is given by `E= E_0 sin [(1.57x 10^7 m^(-1)(x-ct)].` Find the stopping potential when this light is used in an experiment on photoelectric affect with a metal having work - function 1.9 eV.

Options

A. `1.2 V`
B. `1.1 V`
C. `2 V`
D. `2.1 V`

Answer

A

Explanation

`v=(1.57xx10^(7)xx3xx10^(8))/(2pi)=0.75xx10^(15) Hz`
`E=(6.62xx10^(-34)xx0.75xx10^(15))/(1.6xx10^(-19))eV=3.1eV`
`eV_(0)=E-w,V_(0)=1.2V`