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A metal disc of radius $100 \mathrm{~cm}$ is rotated at a constant angular speed of $60 \mathrm{rad} / \mathrm{s}$ in a plane at right angles to an external field of magnetic induction $0.05 \mathrm{~Wb} / \mathrm{m}^{2}$. The emfinduced between the centre and a point on the rim will be
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$1.5 \mathrm{~V}$
Induced emf produced between the centre and a point on the disc is given by $e=\frac{1}{2} \omega B R^{2}$
Putting the values,
$\omega=60 \mathrm{rad} / \mathrm{s}, \mathrm{B}=0.05 \mathrm{~Wb} / \mathrm{m}^{2}$ and $\mathrm{R}=100 \mathrm{~cm}=1 \mathrm{~m}$
We get $\quad e=\frac{1}{2} \times 60 \times 0.05 \times(1)^{2}=1.5 V$
Putting the values,
$\omega=60 \mathrm{rad} / \mathrm{s}, \mathrm{B}=0.05 \mathrm{~Wb} / \mathrm{m}^{2}$ and $\mathrm{R}=100 \mathrm{~cm}=1 \mathrm{~m}$
We get $\quad e=\frac{1}{2} \times 60 \times 0.05 \times(1)^{2}=1.5 V$
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