The work function of a metal is 6.63 eV. The threshold frequency of the metal is:
Correct answer: A. 1.6 × 10^15 Hz
- A. 1.6 × 10^15 Hz
- B. 1.6 × 10^12 Hz
- C. 6.63 × 10^-34 Hz
- D. 1.6 × 10^-19 Hz
Explanation
The work function (W) is the minimum energy required to remove an electron from the surface of a metal. It is related to the threshold frequency (V) by the formula V = W/h, where h is Planck's constant (6.626 × 10^-34 J·s). To find the threshold frequency in Hertz, convert the work function from electronvolts to joules (1 eV = 1.602 × 10^-19 J), and then divide by Planck's constant:V = (6.63 eV × 1.602 × 10^-19 J/eV) / (6.626 × 10^-34 J·s) = 1.6 × 10^15 Hz.Option A is correct because it reflects this calculation. Options B, C, and D are incorrect because they either misrepresent the relationship between work function and threshold frequency or use incorrect values.
Last updated
About Quantum Theory and Radiation
Quantum theory treats electromagnetic radiation as packets of energy called photons, with energy proportional to frequency through E equals hf. The topic covers Planck's hypothesis, photon momentum, the photoelectric effect, threshold frequency, work function and wave particle duality, distinguishing quantised energy exchange from classical continuous radiation.
Practise Dawn of Modern Physics
739 free Dawn of Modern Physics MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Physics questions like this
Physics is on 13 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
0.001 kg mass will be equivalent to_________________?
A black body emitting all the radiation in the visible region appears________.
A black body has the property to _____________ all the radiation entering it.
A black body is one that
A blacksmith is heating an iron axe on a high degree burner. While heating the axe, he noted that different colours are produced. Which of the following colours shows the highest temperature of the iron axe?