An alpha nucleus of energy $\frac{1}{2}mv^2$ bombards a heavy nuclear target of charge $Ze.$ Then the distance of closest approach for the alpha nucleus will be proportional to
$v^2$
$\frac{1}{{Ze}}$
$\frac{1}{m}$
$\;\frac{1}{{{v^4}}}$
Electrons with de-Broglie wavelength $\lambda $ fall on the target an $X-$ ray tube. The cut off wavelength of emitted $X-$ ray is
The ratio of ionization energy of Bohr's hydrogen atom and Bohr's hydrogen like lithium atom is
If radiation of allow wavelengths from ultraviolet to infrared is passed through hydrogen agas at room temperature, absorption lines will be observed in the :
In the spectrum of hydrogen atom, the ratio of the longest wavelength in Lyman series to thelongest wavelength in the Balmer series is
The ratio between total acceleration of the electron in singly ionized helium atom and hydrogen atom (both in ground state) is