$A$ copper disc of radius $0.1 \, m$ is rotated about its centre with $10 \, rev/s$ in a uniform magnetic field of $0.1 \, T$ with its plane perpendicular to the field. The emf induced across the radius of the disc is ........... $V$.

  • A
    $\frac{\pi}{10}$
  • B
    $\frac{\pi}{100}$
  • C
    $\frac{\pi}{1000}$
  • D
    $0$

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