Question

Find the photon energy in units of ev for electromagnetic wave if waves length 40 m. Given h = 6.63 × 10^–34 J.

विकल्प

• 2 × 10⁸ ev

• 3.1 × 10^–8 ev

• 4 × 10^–8 ev

• 4 × 10⁷ ev

Answer 1

3.1 × 10^–8 ev

Explanation:

`lambda = 40, h = 6.63 xx 10^-34`

E = hv = `(hc)/lambda`

`(6.63 xx 10^-34 xx 3 xx 10^8)/(40 xx 1.6 xx 10 - 19) = 3.1 xx 10^-8` ev