Thank you for reporting, we will resolve it shortly
Q.
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 :
$\varepsilon = \frac{d\phi}{dt}$
$ iR = \frac{d\phi}{dt} $
$\int d\phi = R \int idt $
Magnitude of change in flux = R $\times$ area under current vs time graph
$ = 100 \times \frac{1}{2} \times \frac{1}{2} \times 10$
$= 250 \, Wb$
