BITSAT2013PhysicsMagnetic Effects of CurrentActual
Two parallel conductors carry current in opposite directions as shown in figure. One conductor carries a current of 10.0 ~A . Point C is a distance d 2 to the right of the 10.0 ~A current. If d =18 ~cm and I is adjusted so that the magnetic field at Cis zero, the value of the current I is
Options
- A10.0 ~A
- B30.0 ~A
- C8.0 ~A
- D18.0 ~A #
Correct answer
B. 30.0 ~A
Step-by-step solution
The magnetic field at C due to first conductor is B ₁= ₀ 2 I 3 ~d / 2 (since, point C is separated by d + d 2 = 3 ~d 2 from 1 st conductor). The direction of field is perpendicular to the plane of paper and directed outwards. The magnetic field at C due to second conductor is B ₂= ₀ 2 10 ~d / 2 (since, point C is separated by d 2 from 2 nd conductor) The direction of field is perpendicular to the plane of paper and directed inwards. Since, direction of B ₁ and B ₂ at point C is in opposite direction and the magneti