Question

The X-ray spectrum coming from an X-ray tube:

• A. has no minimum or maximum wavelengths
• B. has all wavelengths smaller than a certain maximum wavelength
• C. has all wavelengths greater than a certain minimum wavelength
• D. is monochromatic

Answer 1

Answer: (C)

has all wavelengths greater than a certain minimum wavelength

An X-ray tube is a vacuum tube that converts electrical input power into X-rays. Since X-ray tube cannot provide a monochromatic wave and hence there is a spectrum of waves in it. Energy is inversely proportional to wavelength for X-rays and emitted X-ray waves have energy smaller than energy corresponding to the cutoff wavelength. Hence, all the wavelengths are above the cut off for minimum X-ray wavelength.