Light of wavelength `lambda_(A)` and `lambda_(B)` falls on two identical metal plates A and B respectively . The maximum kinetic energy of photoelectrons in `K_(A)` and `K_(B)` respectively , then which one of the following relations is true ? `(lambda_(A) = 2lambda_(B))`

Options

A. `K_A lt (K_B)/(2)`
B. `2K_A = K_B`
C. `K_A = 2K_B`
D. `K_A gt 2K_B`

Answer

A

Explanation

`KE = (hc)/(lamda) - W_0 rArr K_A = (hc)/(lamda_A) - W_0`
`K_A = (hc)/(2lamda_B) - W_0` ….(i)
`(because lamda_A = 2 lamda_B)`
`K_B = (hc)/(lamda_B) - W_0` …(ii)
From eqn (i) and eq(ii) we have ,
`K_A lt (K_B)/(2)`