Concepts Of Physics MCQ Edition [Volume 2]PhysicsPhotoelectric Effect and Wave–Particle Duality
Visible light encompasses wavelengths ranging from 400 nm to 780 nm . Determine the energy range of the photons of visible light.
Options
- A1.28 10⁻¹⁹ J to 2.50 10⁻¹⁹ J
- B2.56 10⁻¹⁷ J to 5.00 10⁻¹⁷ J
- C5.12 10⁻¹⁹ J to 10.0 10⁻¹⁹ J
- D2.56 10⁻¹⁹ J to 5.00 10⁻¹⁹ J
Correct answer
D. 2.56 10⁻¹⁹ J to 5.00 10⁻¹⁹ J
Step-by-step solution
The energy of a photon is given by the formula E = hc . For the lower limit of wavelength ( = 400 nm ): E_ max = 6.626 10⁻³⁴ 3 10^8 400 10⁻⁹ E_ max = 4.97 10⁻¹⁹ J 5.00 10⁻¹⁹ J For the upper limit of wavelength ( = 780 nm ): E_ min = 6.626 10⁻³⁴ 3 10^8 780 10⁻⁹ E_ min = 2.55 10⁻¹⁹ J 2.56 10⁻¹⁹ J Thus, the energy range of the photons of visible light is 2.56 10⁻¹⁹ J to 5.00 10⁻¹⁹ J .