The ratio of energy of photon of `lambda = 2000 Å` to that of `lambda = 4000 Å` is

Options

A. 2
B. `1//4`
C. 4
D. `1//2`

Answer

A

Explanation

`E_(1) = hv_(1) = h(c )/(lambda_(1)) = (hc)/(2000)`
`E_(2) = hv_(2) = h(c )/(lambda_(2)) = (hc)/(4000)`
`(E_(1))/(E_(2)) = (hc xx 4000)/(2000 xx hc) = 2`