Concepts Of Physics MCQ Edition [Volume 2]PhysicsPhotoelectric Effect and Wave–Particle Duality
The plot of the stopping potential versus the frequency of the light used in an experiment on the photoelectric effect is a straight line. The stopping potential is 0 V at a frequency of 1 10¹⁴ Hz and 1.656 V at a frequency of 5 10¹⁴ Hz . Determine the work function.
Options
- A1.656 eV
- B0.207 eV
- C0.414 eV
- D4.14 eV
Correct answer
C. 0.414 eV
Step-by-step solution
According to Einstein's photoelectric equation: eV = h - From the given graph, the stopping potential is 0 V at the threshold frequency ₀ = 1 10¹⁴ Hz . Thus, the work function is = h ₀ = h(1 10¹⁴) . At = 5 10¹⁴ Hz , the stopping potential is V = 1.656 V . Substituting these values into the equation: e(1.656) = h(5 10¹⁴) - Substituting h(1 10¹⁴) = into the above equation: 1.656 eV = 5 - 4 = 1.656 eV = 1.656 4 eV = 0.414 eV