Question

A circular coil of radius 4 cm and of 20 turns carries a current of 3 amperes. It is placed in a magnetic field of intensity of 0.5 weber/m². The magnetic dipole moment of the coil is
(a) 0.15 ampere-m²
(b) 0.3 ampere-m²
(c) 0.45 ampere-m²
(d) 0.6 ampere-m²

Answer 1

Explanation:

r=4 cm=0.4 meter m=20 terms

I=3 Amp,B=0.5 meter/m

2

magnetic moment =m=nIA=nIπr

2

or magnetic diagonal moment m=20×3×3.14×16×10

−4

meter−m

2

or

m=0.30 Amp−m

2

No use of B

It we ned to calculate magnetic tarque

then

c

=

m

×

B

direction of

m

is given right here rule i.e., for clockwise, current

,

will be into the plane e perpendicular to it.