A metal has a work function `phi_(0)` and its corresponding threshold wavelength is `lambda_(0)`. If the threshold wavelength for a metal whose work function is `(phi_(0))/(3)` is `n lambda_(0)`, then what is the value of n ?

Answer

`3`

Explanation

We know`phi_(0)=(hc)/(lamda_(n))`
`:.(phi_(0))/(phi_(0)^(.))=(lamda_(0)^(.))/(lamda_(0))`
Here `phi_(0)^(.)=(phi_(0))/3`
`:.(lamda_(0)^(.))/(lamda_(0))=3`
`:.lamda_(0)^(.)=3lamda_(0)`
`:.n=3`