i) A circular coil with radius 20 cm is placed with it's plane parallel and between two straight
wires P and Q. The coil carries current I = 0.5A . I for coil is in clockwise direction when viewed
from left side. Wire P is located 40 cm to the left of a circular coil and carries current I = 0.2A
while wire Q is located 80 cm to the right of the circular coil and carries current l = 0.6A. Both
I for P and l for Q are in the same directions into the paper. Determine the resultant of magnetic field at
the centre of a circular coil from the top view.
ii) If the current in wire P is out of the page, determine the resultant of magnetic field at the centre
of a circular coil.

Respuesta :

Answer:

[tex]B=15.433\ T[/tex] inwards when viewing from the left side.

Explanation:

Given:

  • radius of the circular loop, [tex]r=0.2\ m[/tex]
  • current in the coil, [tex]I_c=0.5\ A[/tex]
  • Direction of current is clockwise when viewed from left.
  • Distance of wire P from the loop, [tex]d_p=0.4\ m[/tex]
  • Distance of wire Q from the loop, [tex]d_q=0.8\ m[/tex]
  • current in each wires P & Q, [tex]I=0.2\ A[/tex]

Now the magnetic field in coil will be inwards when viewed from left by the Maxwell's right hand thumb rule.

Magnitude is given by:

[tex]B_c=\frac{\mu_0.I_c}{2R}[/tex]

[tex]B_c=\frac{4\pi\times 10^{-7}\times (0.5)}{2\times 0.2}[/tex]

[tex]B_c=15.7\times 10^{-7}\ T[/tex]

Now the effect of magnetic field due to wire P at the center of the loop:

(We get the effective distance as 0.4+0.2=0.6 m)

[tex]B_P=\frac{\mu_0.I}{2\pi.d_p}[/tex]

[tex]B_P=\frac{4\pi\times 10^{-7}\times (0.2)}{2\pi\times 0.6}[/tex]

[tex]B_P=6.67\times 10^{-8}\ T[/tex] coming out of the loop when viewed from left.

Now the effect of magnetic field due to wire Q at the center of the loop:

(We get the effective distance as 0.8+0.2=1 m)

[tex]B_P=\frac{\mu_0.I}{2\pi.d_q}[/tex]

[tex]B_P=\frac{4\pi\times 10^{-7}\times (0.2)}{2\pi\times 1}[/tex]

[tex]B_P=4\times 10^{-8}\ T[/tex] going in to the loop when viewed from left.

Now the net resultant effect all the magnetic fields:

[tex]B=B_c-B_P+B_Q[/tex]

[tex]B=15.7-0.667+0.4[/tex]

[tex]B=15.433\ T[/tex] inwards when viewing from the left side.