Question

The photoelectric threshold frequency of a metal is n. When light of frequency 4n is incident on the metal, the maximum kinetic energy of the emitted photoelectrons is –

• A. 4 hn
• B. 3 hn
• C. 5 hn
• D. $\frac{5h\nu}{2}$

Answer 1

Answer: (B)

3 hn

Answer 2

E = f + K_max

K_max = 4 hn – hn = 3hn