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

The frequencies of $K_{\alpha}$,$K_{\beta}$,and $L_{\alpha}$ $X$-rays of a material are $\nu_1$,$\nu_2$,and $\nu_3$ respectively. Which of the following relations holds good?

The difference between $\lambda_{K_{\alpha}}$ and $\lambda_{min}$ becomes twice if the accelerating potential changes from $3100 \ V$ to $12400 \ V$. Find $\lambda_{K_{\alpha}}$ in $\mathring{A}$. (Given $hc = 12400 \ eV \mathring{A}$)

The wavelength of the most energetic $X$-rays emitted when a metal target is bombarded by $40 \ keV$ electrons is approximately .............. $\mathring{A}$.

$\Delta \lambda$ is the difference between the wavelength of the $K_\alpha$ line and the minimum wavelength of the continuous $X$-ray spectrum when the $X$-ray tube is operated at a voltage $V$. If the operating voltage is changed to $V / 3$,then the above difference is $\Delta \lambda^{\prime}$. Then:

The wavelength of $K_\alpha$ $X$-rays produced in an $X$-ray tube is $0.76 \ \mathring{A}$. The atomic number of the anode material is: