Question

Q9. A circular coil of N' turns and diameter 'd' carries a current l'. It is unwound and rewound to make another coil of diameter 2d', current l' remaining the same, Calculate the ratio of the magnetic moments of the new coil and the original coil.​

Answer 1

$\large \mathfrak{the \: \: \: required \: \: \: \: ratio \: \: \: is \: } \\ \\ \sf 2 : 1$

2d : d = 2:1