Question

Two wires of same length are shaped into a square and a circle

Answer 1

Answer:

Let length of wire be l. For a square loop, side of square

4

l

.

Hence its magnetic moment

M

sq

=iA=i[

4

l

]

2

=

16

il

2

Radius of a circular loop r=

2π

l

.

Hence, its magnetic moment

M

cir

=iA=iπr

2

M

cir

=iπ[

4π

2

l

2

]=

4π

il

2

⇒

M

cir

M

sq

=

4

π