The self inductance of a coil depends on

A conducting circular coil is place in a uniform magnetic field with the magnetic field initially directed perpendicular to the plane of the coil. In step $A$, the coil is rotated from its initial position by $60^{\circ}$ about its diameter in time $t$. In step $B$, the coil is further rotated about the same axis in the same sense by another $120^{\circ}$ in time $2 t$. Ratio of emf induced in the coil in step $A$ to that in step $B$ is

An alternating emf given by the equation $E=200 \sin (50 \pi t)$ (where, $E$ is in volts and $t$ is in seconds) is applied across a series combination of an inductor and a resistor having inductive reactance $40 \Omega$ and resistance $30 \Omega$ respectively. At time $t=1 \mathrm{~s}$, the power dissipated by the resistor is close to $\left(\cos 53^{\circ}=0.6\right)$

The speed of electromagnetic waves in a medium is $1.5 \times 10^8 \mathrm{~ms}^{-1}$. If relative permittivity of that medium is 2 , then its magnetic susceptibility is (speed of light in vacuum is $3 \times 10^8 \mathrm{~ms}^{-1}$ ).