$X$-rays and $\gamma$-rays of the same energies may be distinguished by

In vacuum,an electron of energy $10 \ keV$ hits a tungsten target. The emitted radiation will be:

If $\lambda_{Cu}$ is the wavelength of the $K_{\alpha}$ $X$-ray line of copper (atomic number $Z = 29$) and $\lambda_{Mo}$ is the wavelength of the $K_{\alpha}$ $X$-ray line of molybdenum (atomic number $Z = 42$),then the ratio $\frac{\lambda_{Cu}}{\lambda_{Mo}}$ is close to:

When cathode rays (tube voltage $\sim 10 \ kV$) collide with the anode of high atomic weight,then we get:

The patient is asked to drink $BaSO_4$ for examining the stomach by $X$-rays because $X$-rays are

The $X$-rays produced by a Coolidge tube consist of . . . . .