Which of the following wavelength falls in X - ray region

Which of the following wavelenght falls in X -rays region?

When a beam of accelerated electrons hits a target , a continuous X - ray spectrum is emitted from the target. Which of the following wavelength is absent in X - ray spectrum , if the X - ray tube is operating at 40,000 "volts" ?

Which of the following wavelength is in the infrared region?

A X-ray tube operates at an accelerating potntial of 20 kV. Which of the following wavelength will be absent in the continuous spectrum of X-rays ?

A X-ray tube operates at an accelerating potntial of 20 kV. Which of the following wavelength will be absent in the continuous spectrum of X-rays ?

X-rays of which of the following wavelengths are hardest

Which of the following has shortest wavelength, microwave, ultraviolet wave and X-rays?

Which of the following has shortest wavelength, microwave, ultraviolet wave and X-rays?

One of the following wavelength is absent and the rest are present in the X-rays coming from a Coolidge tube. Which one is the absent wavelength?