Question:
A circular coil of radius $8.0 \mathrm{~cm}$ and 20 turns is rotated about its vertical diameter with an angular speed of $50 \mathrm{rad} \mathrm{s}^{-1}$ in a uniform horizontal magnetic field of $3.0 \times 10^{-2}$ T. The maximum emf induced the coil will be $\ldots \ldots \ldots \times 10^{-2}$ volt (rounded off to the nearest integer)
Solution:
Maximum $\operatorname{emf} \varepsilon=\mathrm{N} \omega \mathrm{AB}$
$\mathrm{N}=20, \omega=50, \mathrm{~B}=3 \times 10^{-2} \mathrm{~T}$
$\varepsilon=20 \times 50 \times \pi \times(0.08)^{2} \times 3 \times 10^{-2}=60.28 \times 10^{-2}$
Rounded off to nearest integer $=60$
Ans.60