According to Einstein when a photon of light of frequency for wavelength λ is incident on a photo sensitive metal surface of work function ɸ.

Question

Read the paragraph carefully and select the proper choice from given multiple choices. 

According to Einstein when a photon of light of frequency for wavelength λ is incident on a photo sensitive metal surface of work function ɸ. Where ɸ < hf (here h is Plank's constant) then the emission of photo-electrons place takes place. The maximum K.E. of emitted photo electrons is given by K_max = hf – ɸ. If the there hold frequency of metal is f₀ then hf₀ = ɸ. 

(i) A metal of work function 3.3 eV is illuminated by light of wave length 300 nm. The maximum K.E > of photo-electrons is =………eV. (h = 6.6 × 10^–34 J.sec) 

(A) 0.825 (B) 0.413 (C) 1.32 (D) 1.65 

(ii) Stopping potential of emitted photo-electron is =…….V. 

(A) 0.413 (B) 0.825 (C) 1.32 (D) 1.65 

(iii) The threshold frequency f_o = ……… × 1014 Hz. 

(A) 4.0 (B) 4.2 (C) 8.0 (D) 8.4

Answer 1

The correct option is (i) (A) 0.825.