If the frequency of an emitted x-ray is 1.6 x 1016Hz; the accelerating potential is? [e = 1.6 x 10^−19J, h = 6.63 x 10^-34Js]

A. 6630.0V
B. 663.0V
C. 66.3V
D. 6.6V

Correct Answer:

Option C = 66.3V

Explanation
Given f = 1.6 x10¹⁶Hz, h = 6.63 x 10⁻³⁹Js

e = 1.6 x 10⁻¹⁹C, V = ?

V = we=hf/e = 1.6×10¹⁶×6.63×10³⁴/1.6×10⁻¹⁹
= 66.3V