Question

Work function of a body is 4.0 eV. For emission of photoelectron from body, maximum wavelength of light =…………. 

(A) 540 nm 

(B) 400 nm 

(C) 310 nm 

(D) 220 nm

Answer 1

The correct option is (C) 310 nm.

Explanation:

Given: ɸ = 4 eV = 4 × 1.6 × 10^–19 J

ɸ = (hc / λ)

Hence λ = (hc / ɸ)

λ = [{6.62 × 10^–34 × 3 × 10⁸} / {4 × 1.6 × 10^–19}]

= 3.103 × 10^–7 m

= 3.103 × 10^–9 × 10² m

 = 310.3 nm