An X-ray tube operates on 30 kV. The minimum wavelength emitted is `h = 6.6 xx 10^(-34)` Js, c = `3 xx 10^(8)` m/s, e = `1.6 xx 10^(-19)`C.

Options

A. 6.6 `Å`
B. 0.133 `Å`
C. 1.2 `Å`
D. 0.4 `Å`

Answer

D

Explanation

`lambda_(min) = (hc)/(eV) = (6.6 xx 10^(-34) xx 3 xx 10^(8))/(1.6 xx 10^(-19) xx 30 xx 10^(3)) m = 0.4 xx 10^(-10) m = 0.4 Å`