Exercise

The magnetic flux linked with a coil (in $\mathrm{Wb}$) is given by the equation : $\varphi =5t^2+3t+16$. The increase in the induced emf in the coil in the fourth second will be

Elaborate the standard construction details of AC generator.

Explain the working of single phase ac generator with necessary diagram.

Name the essential parts of a dynamo.

A circular ring of diameter $20 \mathrm{cm}$ has a resistance of $0.01 \mathrm{\Omega }$. The charge that will flow through the ring if it is turned from a position perpendicular to a uniform magnetic field of $2.0 \mathrm{T}$ to position parallel to the field is about

A long solenoid of diameter $0.1 \mathrm{m}$ has $2\times {10}^4$ turns per metre. At the centre of the solenoid, a coil of $100$ turns and radius $0.01 \mathrm{m}$ is placed with its axis coinciding with the solenoid axis. The current in the solenoid reduces at a constant rate to $0 \mathrm{A}$ from $4 \mathrm{A}$ in $0.05 \mathrm{s}$. If the resistance of the coil is $10{\mathrm{\pi }}^2 \mathrm{\Omega }$, the total charge flowing through the coil during this time is

A $1.0 \mathrm{m}$ long metallic rod is rotated with an angular frequency of $400 \mathrm{rad} {\mathrm{s}}^{-1}$ about an axis normal to the rod passing through its one end. The other end of the rod is in contact with a circular metallic ring. A constant and uniform field of $0.5 \mathrm{T}$ parallel to the axis exists everywhere. Calculate the emf developed between the centre and the ring.

A circular loop of radius $0.3 \mathrm{cm}$ lies parallel to much bigger circular loop of radius $20 \mathrm{cm}$. The centre of the small loop is on the axis of the bigger loop. The distance between their centres is $15 \mathrm{cm}$. If a current of $2.0 \mathrm{A}$ flows through the smaller loop, then the flux linked with bigger loop is