Question Detail
Question
Given that the wavelength of a beam of radiation is 16 Å. What is the value of the applied potential difference that produced the radiation?
Correct Answer
Option A is the correct answer.
Detailed Explanation
The energy of the photon is E = hc/λ. For an X-ray tube, the kinetic energy of the electron is eV, where V is the potential difference. So eV = hc/λ. λ = 16 Å = 16 × 10^-10 m. h = 6.626 × 10^-34 Js, c = 3 × 10^8 m/s. E = (6.626e-34 × 3e8) / (16e-10) = 1.242375e-16 J. Convert to eV: E = 1.242375e-16 / 1.602e-19 = 775.6 eV. So V ≈ 777 V.
Hint
Use the equation eV = hc/λ, where V is the accelerating voltage.