Exercise 1

A thin disc of radius $R$ and mass $M$ has charge $q$ uniformly distributed on it. It rotates with angular velocity $\omega .$ The ratio of magnetic moment and angular momentum for the disc is

A hollow sphere of mass $m,$ radius $R$ is rotating about its diameter with angular velocity $\omega .$ If charge $Q$ is uniformly distributed over the surface, then magnetic moment of sphere is 

If the planes of two identical concentric coils are perpendicular and the magnetic moment of each coil is $M,$ then the resultant magnetic moment of the two coils will be

In a hydrogen atom, an electron of mass $m$ and charge e revolves in an orbit of radius $r$ making $n$ revolutions per second. If the mass of hydrogen nucleus is $M,$ the magnetic moment associated with the orbital motion of electron is

A wire of length $Lm$ carrying a current $IA,$ is bent in the form of a circle. The magnetic moment is

A rectangular coil of length $0.12 \mathrm{m}$ and width $0.1 \mathrm{m}$ having $50$ turns of wire is suspended vertically in a uniform magnetic field of strength $0.2$ Weber$/{\mathrm{m}}^2$. The coil carries a current of $2 \mathrm{A}$. If the plane of the coil is inclined at an angle of $30°$ with the direction of the field, the torque required to keep the coil in stable equilibrium will be

A galvanometer gives full scale deflection with $0.2 \mathrm{A}$ in its coil. The resistance of its coil is $10 \mathrm{\Omega }.$. How much shunt resistance is required to convert it into an ammeter to read current up to $1.8 \mathrm{A} ?$

A galvanometer of resistance $2\mathrm{\Omega }$ and having full scale deflection for a current of $100 \mathrm{mA}$ can be converted into a volt meter of range $5$ Volt by connecting a resistance $R$ in series with galvanometer. The resistance $\text{'}R\text{'}$ is