On increasing the number of electrons striking the anode of an $X-$ray tube,which one of the following parameters of the resulting $X-$rays would increase?

The voltage applied across an $X$-ray tube is nearly......$V$.

When $X-$rays pass through a strong uniform magnetic field,then they

An $X$-ray tube operates at $50 \, kV$ and $20 \, mA$. The target material has a mass of $1.0 \, kg$ and a specific heat capacity of $495 \, J \cdot kg^{-1} \cdot ^\circ C^{-1}$. One percent of the applied electrical power is converted into $X$-rays,and the remaining energy is used to heat the target. Then:
$(1)$ $A$ suitable target material should have a high melting point.
$(2)$ $A$ suitable target material should have low thermal conductivity.
$(3)$ The rate of rise of temperature of the target is $2 \, ^\circ C/s$.
$(4)$ The minimum wavelength of the emitted $X$-rays is $0.25 \, \mathring{A}$.

$X$-rays are:

The emission of continuous $X$-rays is due to: