A domain in a ferromagnetic substance is in the form of a cube of side $1 \mu \mathrm{~m}$. If it contains $8 \times 10^{10}$ atoms and each atomic dipole has a dipole moment of $9 \times 10^{-24} \mathrm{Am}^2$, then the magnetisation of the domain is
If the surface tension of a soap solution is $3 \times 10^{-2} \mathrm{~N} / \mathrm{m}$ then the work done in forming a soap film of $20 \mathrm{~cm} \times 5 \mathrm{~cm}$ will be
The compressibility of water is $5 \times 10^{-10} \mathrm{~m}^2 / \mathrm{N}$. Pressure of $15 \times 10^6 \mathrm{~Pa}$ is applied on 100 mL volume of water. The change in the volume of water is
Two bodies $A$ and $B$ of equal mass are suspended from two separate massles springs of force constant $k_1$ and $k_2$, respectively. The bodies oscillate vertically such that their maximum velocities are equal. The ratio of the amplitudes of body $A$ to that of body $B$ is