Question

2 concentric circular coils of radius 25 cm and 15 cm and carry currents 10A and 15A respectively A has 24 turns and B has 18 turns the direction of the current is in opposite order the magnetic induction at the common centre of the coils is

Answer 1

Answer:

Given : for coil A:

VA=25cm=0.25m

nA=24nA=24

IA=10AI=10A

For coil B:

rb=15cm=0.15m

nb=18nb=18

Ib=15AI=15A

Magnetic field at the center of coil x

BA=µ0 /4π*2Ia πna/ra

=10−7×2×10×3.14×24/0.25

=6.028×10^−4

=6.028×10^−4T

Magnetic field at the center of coil B

B= µ0 /4π*2Ib πnb/rb

=10−7×2×3.14×15×18

=11.30×10−4T

Hence the net magnetic field at the center

Bb−Ba=(11.30×10−4−6.028×10−4)T

=5.27×10−4T