Question 311: Electromagnetic Induction

Question

A coil has an area $$0.06 \mathrm{~m}^2$$ and it has 600 turns. After placing the coil in a magnetic field of strength $$5 	imes 10^{-5} \mathrm{Wbm}^{-2}$$, it is rotated through $$90^{\circ}$$ in 0.2 second. The magnitude of average e.m.f induced in the coil is
$$\left[\cos 0^{\circ}=\sin 90^{\circ}=1 	ext { and } \sin 0^{\circ}=\cos 90^{\circ}=0ight]$$

Accepted Answer

Induced emf $$\mathrm{e}=\frac{-\mathrm{N}\left(\phi_2-\phi_1ight)}{\mathrm{t}}=\frac{-\mathrm{NBA}\left(\cos 	heta_2-\cos 	heta_1ight)}{\mathrm{t}}$$
Assuming that the coil was initially placed perpendicular to the magnetic flux $$	heta_1=0^{\circ}$$ and $$	heta_2=90^{\circ}$$.
$$\begin{aligned}
e & =\frac{-\mathrm{NBA}\left(\cos 90^{\circ}-\cos 0^{\circ}ight)}{t} \
& =\frac{-\mathrm{NBA}(0-1)}{\mathrm{t}}=\frac{\mathrm{NBA}}{\mathrm{t}} \
& =\frac{600 	imes 5 	imes 10^{-5} 	imes 0.06}{0.2}=9 	imes 10^{-3} \mathrm{~V}
\end{aligned}$$

Answer

$$12 	imes 10^{-3} \mathrm{~V}$$

Answer

$$3 \mathrm{~mV}$$

Answer

$$3 \mathrm{~V}$$

Answer

$$9 	imes 10^{-3} \mathrm{~V}$$

Electromagnetic Induction

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