question_answer

In a coil of resistance \[100\,\Omega ,\] a current is induced by changing the magnetic flux through it as shown in the figure. The magnitude of change in flux through the coil is:                                [JEE Main 2017]

A) 250 Wb

B) 275 Wb

C) 200 Wb

D) 225 Wb

Correct Answer: A

Solution :

[a]

\[q=\frac{\Delta \text{o}|}{R}\]

\[\Delta \text{o }\!\!|\!\!\text{ }=\]change in flux

\[q=\int_{{}}^{{}}{I\,dt}\]

= Area of current-time graph

\[=\frac{1}{2}\times 10\times 0.5=2.5\]coloumb

\[q=\frac{\Delta \text{o}|}{R}\]

\[\Delta \text{o }\!\!|\!\!\text{ =2}\text{.5}\times 100=250\,Wb\]