MHT CET202613 April 2026Evening ShiftPhysicsDual Nature of MatterActual
The threshold frequency of metal is f₀ . When the light of frequency 2f₀ is incident on the metal plate, the maximum velocity of photoelectron is v₁ . When the frequency of incident radiation is increased to 5f₀ the maximum velocity of photoelectrons emitted is v₂ . The ratio v₁ to v₂ is
Options
- A1:2
- B1:8
- C1:16
- D1:4
Correct answer
A. 1:2
Step-by-step solution
Using Einstein's photoelectric equation: K_ = hf - hf₀ For incident frequency 2f₀ : 1 2 mv₁^2 = h(2f₀) - hf₀ = hf₀ For incident frequency 5f₀ : 1 2 mv₂^2 = h(5f₀) - hf₀ = 4hf₀ Taking the ratio of the two equations: v₁^2 v₂^2 = hf₀ 4hf₀ = 1 4 v₁ v₂ = 1 2 Answer: 1:2