Question

A metallic rod of 1 m length is rotated with a frequency of 50 rev/s, with one end hinged at the centre and the other end at the circumference of a circular metallic ring of radius 1 m, about an axis passing through the centre and perpendicular to the plane of the ring (fig. 6.11). A constant and uniform magnetic field of 1 T parallel to the axis is present everywhere. What is the emf between the centre and the metallic ring?

Answer 1

Dear Student

$$\begin{gathered} lettheemf\epsilon =\frac{1}{2}B\omega R^2 \\ Bisthemagneticfield \\ \omega isthemagneticfield \\ Ristheradius \\ then \\ \epsilon =\frac{1}{2}B\left(2\pi f\right)R^2 \\ f=50rev/s \\ B=1T \\ R=0.5m(suggestedbythestudent) \\ \epsilon =\frac{1}{2}\times 1.0\times 2\pi \times 50\times (\frac{1}{2}{)}^2 \\ \epsilon =39.25V \\ IfR=1masgiveninquestionthen \\ \epsilon =157V \end{gathered}$$

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