ExamBro
ExamBro
MHT CET · Physics · Dual Nature of Matter

Two photons having energies twice and thrice the work function of metal are incident one after another on the metal surface. Then the ratio of maximum velocities of the photoelectrons emitted in the two cases is respectively

  1. A \(\sqrt{3}: 3\)
  2. B \(\sqrt{2}: \sqrt{3}\)
  3. C \(1: \sqrt{2}\)
  4. D \(\sqrt{3}: 1\)
Verified Solution

Answer & Solution

Correct Answer

(C) \(1: \sqrt{2}\)

Step-by-step Solution

Detailed explanation

\(\begin{aligned} & K \cdot E_{\max }=h v-\phi_0 \\ & \text {Given: } E_1=2 \phi_0 \text { and } E_2=3 \phi_0 \\ & \Rightarrow K \cdot E_1=2 \phi_0-\phi_0=\phi_0 \\ & \Rightarrow K \cdot E_2=3 \phi_0-\phi_0=2 \phi_0 \\ & \text {but, } K \cdot E_1=\frac{1}{2} m v_1^2 \text { and } K \cdot E_2=\frac{1}{2} m v_2^2 \\ \therefore \quad & \frac{K \cdot E_1}{K \cdot E_2}=\frac{V_1^2}{V_2^2}=\frac{1}{2} \\ \therefore \quad & \frac{V_1}{V_2}=\frac{1}{\sqrt{2}}\end{aligned}\)
Same subject
Explore more questions on app