**Question:**

Two identical wires A and B, each of length ‘ $l$ ‘, carry the same current $\mathrm{I}$. Wire $\mathrm{A}$ is bent into a circle of radius $\mathrm{R}$ and wire $\mathrm{B}$ is bent to form a square of side ‘ $\mathrm{a}$ ‘. If $\mathrm{B}_{\mathrm{A}}$ and $\mathrm{B}_{\mathrm{B}}$ are the values of magnetic field at the centres of the circle and square respectively, then the ratio $\frac{\mathrm{B}_{\mathrm{A}}}{\mathrm{B}_{\mathrm{B}}}$ is:

Correct Option: 2

**Solution:**

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