Physics

Problem

Two identical wires are bent into single circular loops of radii

5\,\text{cm}

and

12\,\text{cm}

respectively. The same current of

4\,\text{A}

flows through each loop. What is the ratio of the magnetic field at the centre of the smaller loop to that at the centre of the larger loop? a)

0.17

4.8

2.4

0.42