JEE Main202430 Jan 2024Morning ShiftPhysicsMagnetic Effects of CurrentActual
Two insulated circular loop A and B radius a carrying a current of I in the anti clockwise direction as shown in figure. The magnitude of the magnetic induction at the centre will be:
Options
- A2 μ 0 I a
- Bμ 0 I 2 a
- Cμ 0 I 2 a
- D2 μ 0 I a
Correct answer
C. μ 0 I 2 a
Step-by-step solution
Right hand thumb rule states that, “If you imagine holding a current carrying wire in your right-hand with your thumb pointing towards the direction of electric current flow then the direction in which your fingers curl, gives the direction of lines of force of the magnetic field”. In this case, direciton of magnetic field at the centre for both wires is as shown below. Magnetic field due to a circular wire is given by, B A = B B = μ 0 I 2 a As both magnetic field lines at centre are perpendicular, therefore ∵ B n