Question

Light of frequency 1.5 times the threshold frequency is incident on a photosensitive material, photoelectric current is emitted. If the frequency of light is halved and intensity is doubled, the photoelectric current becomes –

• A. 4 times the original current
• B. 2 times the original current
• C. Half the original current
• D. Zero times the original current

Answer 1

Answer: (D)

Zero times the original current

Answer 2

n = 1.5 n₀

if it is halved then n' = 0.75 n₀

Which is less than n₀.

So current should be zero.