Question : The magnetic field at the centre, P will be
a) µ₀/4π
b) µ₀/π
c) µ₀/2π
d) 4µ₀π
Doubt by Trishna
Solution :
We know, magnetic field due to a straight current carrying conductor is given by
B=µ₀I/2πr
The direction of magnetic field is given by Right Hand Thumb Rule
Here
I1=5.0 A
I2=2.5 A
r1=r2=r=5/2=2.5 m
Magnetic Field at Point P due to First (Left) Wire
B1=µ₀I1/2πr1
B1=µ₀I1/2πr (Inside the Plane of screen)
Similarly
B2=µ₀I2/2πr (Outside the Plane of screen)
Net Magnetic Field at Point P
B=B1-B2
B=µ₀I1/2πr-µ₀I2/2πr
B=[µ₀/2πr][I1-I2]
B=[µ₀/2π(2.5)][5-2.5]
B=[µ₀/2π(2.5)][2.5]
B=µ₀/2π (Inside the Plane of Paper)
B=[µ₀/2π(2.5)][2.5]
B=µ₀/2π (Inside the Plane of Paper)
Hence, c) µ₀/2π is the correct option.
