Question

Some equipotential surfaces of the magnetic scalar potential are shown in figure.Magnetic field at a point in the region is

• A. ${10}^{-4}$ T
• B. $0.5\times {10}^{-4}$ T
• C. $2\times {10}^{-4}$ T
• D. None of these

Answer 1

The correct option is C $2\times {10}^{-4}$ T

As is clear from figure
$△V=(0.2-0.1){10}^{-4}Tm$
$△x=xsin{30}^0=0.1\times \frac{1}{2}$
$\therefore |B|=\frac{△V}{△x}=\frac{0.1\times {10}^{-4}}{0.1/2}=2\times {10}^{-4}T$