Question

What is the lower range of wavelength of the X-rays?

(a) 40 x 10^-7 cm

(b) 40 x 10^-8 cm

(c) 40 x 10^-9 cm

(d) 40 x 10^-10 cm

This question was addressed to me during an online interview.

My query is from Radiography topic in section Non Destructive Techniques of Casting-Forming-Welding II

Answer 1

Right choice is (b) 40 x 10^-8 cm

To explain: The X-rays are considered to be rays having a short wavelength. These X-rays can be produced with the help of an X-ray tube or a Cobalt-60 isotope. The longest wavelength of an X-ray is 40 x 10^-8 cm.