The reason for the double helical structure of $DNA$ is the operation of

$A$ coil of radius '$r$' is placed on another coil (whose radius is '$R$' and current through it is changing) so that their centers coincide. $(R \gg r)$. If both are coplanar,then the mutual inductance between them is proportional to

An electron beam travels with a velocity of $1.6 \times 10^7 \ m/s$ perpendicularly to a magnetic field of intensity $0.1 \ T$. Calculate the radius of the path of the electron beam. (Given: $m_e = 9 \times 10^{-31} \ kg$,$e = 1.6 \times 10^{-19} \ C$)

An ideal gas follows a process $PT = \text{constant}$. The correct graph between pressure $(P)$ and volume $(V)$ is:

The structure of $XeOF_4$ is

Which of the following is the correct electronic configuration of a neutral $Carbon$ atom in its ground state?