The apparent wavelength of light from a star moving away from the earth is $0.02 \%$ more than the actual wavelength. The velocity of star is $\left[\mathrm{c}=\right.$ velocity of light $\left.=3 \times 10^8 \mathrm{~m} / \mathrm{s}\right]$

A parallel plate air capacitor has capacitance $C_P$. It is equally filled with parallel layers of materials of dielectric constants $\mathrm{K}_1$ and $\mathrm{K}_2$. Now its capacity becomes $C_K$. The ratio $C_P$ to $C_K$ is

The change in the internal energy of the mass of gas, when the volume changes from V to 2 V at constant pressure P is $\left(\gamma=\frac{\mathrm{Cp}}{\mathrm{Cv}}\right)$

If the length of the potentiometer wire is increased by keeping constant potential difference across the wire, then