CUET · PHYSICS · PYQ PAPER 2023
The work function of a photoelectric surface is 3.3 eV. The value of the threshold frequency for the surface is :
- A \( 8 \times 10^{14} \, \text{Hz} \)
- B \( 5 \times 10^{16} \, \text{Hz} \)
- C \( 4 \times 10^{11} \, \text{Hz} \)
- D \( 8 \times 10^{10} \, \text{Hz} \)
Answer & Solution
Correct Answer
(A) \( 8 \times 10^{14} \, \text{Hz} \)
Step-by-step Solution
Detailed explanation
\( \phi = hf_0 \) \( f_0 = \frac{\phi}{h} = \frac{3.3 \, \text{eV} \times 1.602 \times 10^{-19} \, \text{J/eV}}{6.626 \times 10^{-34} \, \text{J} \cdot \text{s}} \) \( f_0 \approx 8 \times 10^{14} \, \text{Hz} \)
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