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

When $X$-rays from a Coolidge tube pass through an aluminum foil of thickness $0.3 \, mm$,$50\%$ of the $X$-rays are transmitted. If the potential difference between the target and the cathode is increased,the fraction of $X$-rays transmitted through the same foil will be .......

In an $X-ray$ tube, the voltage is $5 \, kV$ and the current is $3.2 \, mA$. The number of electrons striking the anode per second is:

If the voltage of an $X$-ray tube is doubled,the intensity of the $X$-rays will be ...... .

The characteristic $X-$ray radiation is emitted,when

If the frequency of the $K_\alpha$ line of an element with $Z = 64$ is $\nu_\alpha$ and the frequency of the $K_\alpha$ line of an element with $Z = 80$ is $\nu'_\alpha$,then the ratio of their frequencies is: