Question

In a coil of resistance $10\Omega$, the induced current developed by changing magnetic flux through it, as shown in figure is a function of time. The magnitude of change in flux through the coil in $\text{weber}$ is:

• A. $8$
• B. $2$
• C. $6$
• D. $4$

Answer 1

The correct option is B $2$

We know that,

$q=$Area under $i-t$ graph

$q=\frac{1}{2}\times 4\times 0.1=0.2\text{C}$

Now, $q=\frac{\Delta \varphi }{R}$

$\Rightarrow \Delta \varphi =qR=\left(0.2\text{C}\right)\left(10\Omega \right)$

$\Delta \varphi =2\text{weber}$

Hence, option $\left(B\right)$ is the correct answer.