question_answer

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

A)            \[{{10}^{-4}}T\]                   

B)            \[2\times {{10}^{-4}}T\]

C)            \[0.5\times {{10}^{-4}}T\]      

D)            None of these

Correct Answer: B

Solution :

           \[|B|\,=\frac{\Delta V}{\Delta x}=\frac{0.1\times {{10}^{-4}}}{0.1\ \sin {{30}^{o}}}=2\times {{10}^{-4}}T\]