Question 276: Electromagnetic Induction

Question

A metal disc of radius $$R$$ rotates with an angular velocity $$\omega$$ about an axis perpendicular to its plane passing through its centre in a magnetic field of induction $$B$$ acting perpendicular to the plane of the disc. The magnitude of induced emf between the rim and axis of the disc is

Accepted Answer

Total magnetic flux linked
$$\begin{aligned}
\phi & =B A \
	herefore 	ext { induced emf, }|e| & =\frac{\Delta \phi}{\Delta t}=\frac{\Delta B A}{\Delta t}=B \cdot \frac{\Delta A}{\Delta T} \
& =B \cdot \frac{\pi R^2}{\left(\frac{2 \pi}{\omega}ight)}=\frac{B \omega R^2}{2}
\end{aligned}$$

Answer

$$\pi B R^2$$

Answer

$$\frac{2 \pi^2 B R^2}{\omega}$$

Answer

$$\pi B R^2 \omega$$

Answer

$$\frac{B R^2 \omega}{2}$$

Electromagnetic Induction

A metal disc of radius $R rotates with an angular velocity \omega about an axis perpendicular to its plane passing through its centre in a magnetic field of induction B$ acting perpendicular to the plane of the disc. The magnitude of induced emf between the rim and axis of the disc is

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