CBSE Class 12 · 2024 · Modern PhysicsMultiple Choice

The variation of the stopping potential $V_0$ with the frequency $\nu$ of the incident radiation for four metals A, B, C and D is shown in the figure. For the same frequency of incident radiation producing photo-electrons in all metals, the kinetic energy of photo-electrons will …

The energy of an electron in the ground state of a hydrogen atom is $-13.6$ eV. The kinetic and potential energy of the electron in the first excited state will be

Assertion (A): An alpha particle is moving towards a gold nucleus. The impact parameter is maximum for the scattering angle of $180^{\circ }$.
Reason (R): The impact parameter in an alpha particle scattering experiment does not depend upon the atomic number of the target nucleus.

Calculate the energy released / absorbed (in MeV) in the nuclear reaction ${}_1^1\mathrm{H}+{}_1^3\mathrm{H}\to {}_1^2\mathrm{H}+{}_1^2\mathrm{H}$. Given $m{(}_1^1\mathrm{H})=1.007825u$, $m{(}_1^2\mathrm{H})=2.014102u$, …

A proton of energy 1.6 MeV approaches a gold nucleus $(Z=79)$. Find the distance of its closest approach.

A photosensitive surface of work function 2.1 eV is irradiated by radiation of wavelength 150 nm. Calculate
(i) the threshold wavelength,
(ii) the energy (in eV) of an incident photon, and
(iii) the maximum kinetic energy of the emitted photoelectron.