Question

The difference between soft and hard X-rays is of

• A. velocity
• B. intensity
• C. frequency
• D. polarization

Answer 1

Answer: (C)

The penetrating power of X-rays depends upon their wavelength. The frequency of the longer wavelength (approximately $mg{R}_e.$ ). X-rays is lower and so their energy is smaller. Hence, their penetrating power is weaker and they are called soft or less penetrating X-rays. The penetrating power of the shorter wavelength (approximately $R_e$ ). X-rays is stronger and they are called hard or highly penetrating X-rays. Hence, the difference between the two is only of frequency.