In an $AC$ generator,a coil with $N$ turns,all of the same area $A$ and total resistance $R$,rotates with frequency $\omega$ in a magnetic field $B$. The maximum value of emf generated in the coil is

An elliptical loop having resistance $R$,semi-major axis $a$,and semi-minor axis $b$ is placed in a magnetic field as shown in the figure. If the loop is rotated about the $x$-axis with angular frequency $\omega$,the average power loss in the loop due to Joule heating is:

$A$ circular coil of resistance $R$,area $A$,and number of turns $N$ is rotated about its vertical diameter with angular speed $\omega$ in a uniform magnetic field of magnitude $B$. The average power dissipated in a complete cycle is:

$A$ coil of area $25 \; cm \times 10 \; cm$ having $300$ turns is rotated in a magnetic field of $4 \times 10^{-2} \; T$ with an angular speed of $50 \; rps$. What is the maximum $emf$ induced (in $\pi \; V$)?

$A$ planar loop made of wire is rotating in a uniform magnetic field. At time $t=0$,the plane of the loop is perpendicular to the magnetic field. If the loop is rotating about an axis passing through its plane with a period of $10 \; s$,at which of the following times will the induced electromotive force (emf) be maximum and minimum,respectively?

$A$ coil of area $A$ and $N$ turns is rotating with angular velocity $\omega$ in a uniform magnetic field $\overrightarrow{B}$ about an axis perpendicular to $\vec{B}$. Magnetic flux $\varphi$ and induced emf $\varepsilon$ across it,at an instant when $\overrightarrow{B}$ is parallel to the plane of the coil,are: