Question

​a conducting ring of radius b is placed coaxially in a long solenoid of radius a (a<b) having n turns per unit length. A current i = io cos omega t flows through the solenoid. the induced emf in the ring is

Answer 1

Dear Student,
$$\begin{gathered} Magneticfieldinsidethesolenoid={\mu }_{0}ni={\mu }_{0}n{i}_0\cos \left(\omega t\right) \\ nowenducedemf=-\frac{d\phi }{dt}=-\frac{d\left(\pi b^2{\mu }_{0}n{i}_0\cos \left(\omega t\right)\right)}{dt}=\omega \pi b^2{\mu }_{0}n{i}_0\sin \left(\omega t\right) \end{gathered}$$
Regard