Hard `X` -rays for the study of fractures in bones should have a minimum wavelength of `10^(-11) m`. The accelerating voltage for electrons in `X` -ray machine should be

Options

A. `lt 124.2 kV`
B. `gt 124 2 kV`
C. between 60 kV and 70 kV
D. `=100 kV`

Answer

B

Explanation

`lambda_("min") =(hc)/(eV)=(1.42xx10^(-6))/(V)` ltbgt `V=(1.424xx10^(-6))/(10^(-11))=124.2KV`
The accelerating volage for electrons in X-ray machine should be greater than `124.2 V`