Question

If $R=0.01\Omega$, the magnitude and direction of current flowing in the loop are

• A. $1A$, clockwise
• B. $1A$, anticlockwise
• C. $10A$, clockwise
• D. $10A$, anticlockwise
• E. $none$

Answer 1

Answer: (C)

$10A$, clockwise

As the area of the loop goes to zero, the flux associated with it goes to zero. To calculate the induced current:-

$\Delta \varphi =B\Delta A=1\times \pi \times (0.1{)}^{2}T{m}^2$

$\Delta t=0.314s$

$\xi =\frac{\Delta \varphi }{\Delta t}=\frac{1\times 3.14\times 0.01}{0.314}V$

$\xi =0.1V$

$I=\frac{\xi }{R}=\frac{0.1}{0.01}A=10A$

To decide the direction, we can easily see that it will try to restore the flux in the direction inside the plane of paper and thereby by right hand thumb rule, we will get the direction as clockwise