Question

An X-ray tube is operated at $6.6kV$. In the continuous spectrum of the emitted X-rays, which of the following frequencies will be missing?

• A. ${10}^{18}Hz$
• B. $1.5\times {10}^{18}Hz$
• C. $2\times {10}^{18}Hz$
• D. $2.5\times {10}^{18}Hz$

Answer 1

Answer: (C), (D)

The correct options are
C $2\times {10}^{18}Hz$
D $2.5\times {10}^{18}Hz$

The maximum frequency in the X-ray emission by an X-ray tube operating at V volt is given by ,

$f_{max}=\frac{eV}{h}$

given $V=6.6kV=6.6\times {10}^{3V}$ and we have $h=6.6\times {10}^{-34}J-s,e=1.6\times {10}^{-19}C$ ,

therefore $f_{max}=\frac{1.6\times {10}^{-19}\times 6.6\times {10}^3}{6.6\times {10}^{-34}}=1.6\times {10}^{18}Hz$

Therefore , the frequencies above the maximum frequency $1.6\times {10}^{18}Hz$ will be missing .