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. `lt124` kV
B. `gt124` kV
C. between `60 kV and 70 kV`
D. `=100 kV`

Answer

D

Explanation

As `r=(mv)/(qB),` i.e., `rprop m//q`
So, `(r_(1))/(r_(2))=(m_(1))/(m_(2))xx(q_(2))/(q_(1))=(24xx2e)/(22xxe)=(24)/(11)`