Q. Hard $X$-rays for the study of factures in bones should have a minimum wavelength of $10^{- 11}m.$ The accelerating voltage for electrons in $X$-ray machine should be

A) $< 124.2\ kV$
B) $> 124.2\ kV$
C) Between $60\ kV$ and $70\ kV$
D) $= 100\ kV$
Explanation

(a) $V_{max\ } = \frac{12400 \times 10^{- 10}}{10^{- 11}} = 124kV \Rightarrow v < 124kV$

Dr. Abubacker
Reviewed by Dr. Abubacker

Physics Educator & NEET/JEE Specialist

Ph.D. in Physics with 19+ years of teaching experience.