AP EAPCET 07-Jul-2022 Shift 1 Paper

111. (c) Magnetic field produced by a magnet on its axis and its equator are given by
Baxis=

µ0

4π

⋅

2M

r13

Bequator=

µ0

4π

=

M

r23

Baxis=Bequator×

2r23

r13

...(i)
Where,
M=
magnetic dipole moment of magnet and
r=
distance from Centre of magnet

So,

Baxis

Bequator

=

µ0 4π 2M r13

µ0 4π ⋅ M r23

=

2r23

r13

Baxis=Bequator×

2r23

r13

...(i)
Here, given
Bequator=6.4×10−5T
r1=40‌cm=40×10−2m
r2=20‌cm=20×10−2m
So from Eq.(i), we have,
Baxis=

6.4×10−5×2×(20×10−2)3

(40×10−2)3

=

6.4×10−5×2×23

43

=1.6×10−5T