Question
A massless square loop, of wire of resistance $10 \Omega$, supporting a mass of $1 \mathrm{~g}$, hangs vertically with one of its sides in a uniform magnetic field of $10^{3} \mathrm{G}$, directed outwards in the shaded region. A dc voltage $\mathrm{V}$ is applied to the loop. For what value of $\mathrm{V}$, the magnetic force will exactly balance the weight of the supporting mass of $1 \mathrm{~g}$ ?
(If sides of the loop $=10 \mathrm{~cm}, \mathrm{~g}=10 \mathrm{~ms}^{-2}$)