The angle of incidence at which reflected light is totally polarized for reflection from air to glass (refractive index $n$) is

The moment of inertia of a uniform circular disc is maximum about an axis perpendicular to the disc and passing through which of the following points?

The decreasing order of bond dissociation energies of $C-C$,$C-H$,and $H-H$ bonds is:

$A$ thin flexible wire of length $L$ is connected to two adjacent fixed points and carries a current $I$ in the clockwise direction as shown. When the system is placed in a uniform magnetic field of strength $B$ directed into the plane of the paper,the wire takes the shape of a circle. The tension in the wire after acquiring the circular shape is

$A$ light string passing over a smooth light pulley connects two blocks of masses $m_1$ and $m_2$ (vertically). If the acceleration of the system is $g / 8$,then the ratio of the masses $m_1 : m_2$ (assuming $m_1 > m_2$) is:

The maximum number of sub-levels,orbitals and electrons in $N$ shell of an atom are respectively