Question 237: Electromagnetic Induction

Question

A coil of resistance $250 \Omega$ is placed in a magnetic field. If the magnetic flux $(\phi)$ linked with the coil varies with time $t(\mathrm{~s})$ as $\phi=50 \mathrm{t}^2+7$. The current in the coil at $t=4 \mathrm{~s}$ is

Accepted Answer

Induced e.m.f. is given as $|e|=\frac{\mathrm{d} \phi}{\mathrm{dt}}$
Given, $\phi=50 \mathrm{t}^2+7$
$	herefore \quad|e|=\frac{d}{d t}\left(50 t^2+7ight)=100 \mathrm{t}$
For $\mathrm{t}=4 \mathrm{~s}$, $\mathrm{e}=100(4)=400 \mathrm{~V}$
Current, $\mathrm{I}=\frac{\mathrm{V}}{\mathrm{R}}=\frac{400}{250}=1.6 \mathrm{~A}$

Answer

1.3 A

Answer

$\quad 1.4 \mathrm{~A}$

Answer

$\quad 1.5 \mathrm{~A}$

Answer

1.6 A

Electromagnetic Induction

A coil of resistance 250 \Omega is placed in a magnetic field. If the magnetic flux (\phi) linked with the coil varies with time t(\mathrm{~s}) as \phi=50 \mathrm{t}^2+7. The current in the coil at t=4 \mathrm{~s} is

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