JEE Main20231 Feb 2023Morning ShiftPhysicsMagnetic Effects of CurrentActual
Find the magnetic field at the point P in figure. The curved portion is a semicircle connected to two long straight wires.
Options
- Aμ 0 i 2 r 1 + 2 π
- Bμ 0 i 2 r 1 + 1 π
- Cμ 0 i 2 r 1 2 + 1 2 π
- Dμ 0 i 2 r 1 2 + 1 π
Correct answer
C. μ 0 i 2 r 1 2 + 1 2 π
Step-by-step solution
Magnitude of magnetic field due to semi-infinite portion of wire AB at point C is B 1 = μ 0 i 4 π r Magnitude of magnetic field due to semicircular arc BD at point C is B 2 = μ 0 i 4 r Magnitude of magnetic field due to semi-infinite portion DE at point C is 0. Using right-hand rule, it can be seen that directions of B 1 → and B 2 → are both outwards from the plane. Therefore, the magnitude of net magnetic field at point C is B = B 1 + B 2 = μ 0 i 2 r 1 2 + 1 2 π