Question

A current $i$ enters at one of the vertex of a cube made of wires of equal length $a$ leaves through opposite diagonal as shown in diagram. The magnetic field at the centre of the cube is :

• A. $\frac{12{\mu }_{0}i}{\sqrt{2}\pi a}$
• B. $\frac{6{\mu }_{0}i}{\sqrt{2}\pi a}$
• C. $\frac{6{\mu }_{0}i}{\pi a}$
• D. $zero$

Answer 1

The correct option is D $zero$

Symmetrically situated current elements carry equal currents in the same direction and will cancel each other.
Hence, magnetic field at the center will be zero.