Question

For a photosensitive surface, the work function is 3.3 × 10^-19 J. Calculate the threshold frequency.

(a) 15 × 10^14 Hz

(b) 25 × 10^14 Hz

(c) 5 × 10^14 Hz

(d) 55 × 10^14 Hz

This question was posed to me during an online exam.

My doubt stems from Einstein’s Photoelectric Equation : Energy Quantum of Radiation topic in chapter Dual Nature of Radiation and Matter of Physics – Class 12

Answer 1

Right answer is (c) 5 × 10^14 Hz

The explanation is: Threshold frequency is given as:

v0 = \(\frac {W_0}{h}\)

v0 = \(\frac {W_0}{h}\)

v0 = \(\frac {(3.3 \times 10^{-19})}{(6.6 \times 10^{-34})}\)

v0 = 5 × 10^14 Hz.