Question 170: Electromagnetic Induction

Question

The magnetic field B crossing normally a square metallic plate of area $$4 \mathrm{~m}^{2}$$ is changing with time as shown in figure. The magnitude of induced emf in the plate during $$\mathrm{t}=2 s$$ to $$\mathrm{t}=4 s$$, is __________ $$\mathrm{mV}$$.

Accepted Answer

$$
\begin{aligned}
& \mathrm{m}=	an 	heta=\frac{10}{5}=2 \\
& \mathrm{~B}=\mathrm{mt} \\
& \mathrm{B}=2 \mathrm{t}
\end{aligned}
$$
$$
\begin{aligned}
& \varepsilon=\left|\frac{\mathrm{d} \phi}{\mathrm{dt}}ight|=\frac{\mathrm{d}(\mathrm{BA})}{\mathrm{dt}}=\frac{\mathrm{AdB}}{\mathrm{dt}} \\
& \varepsilon=\frac{4 \mathrm{~d}(2 \mathrm{t})}{\mathrm{dt}}=4 	imes 2=8 \mathrm{mV}
\end{aligned}
$$

Electromagnetic Induction

The magnetic field B crossing normally a square metallic plate of area $4 \mathrm{~m}^{2} is changing with time as shown in figure. The magnitude of induced emf in the plate during \mathrm{t}=2 s to \mathrm{t}=4 s, is __________ \mathrm{mV}$.

Choose the correct answer: