MHT CET202523 Apr 2025Evening ShiftPhysicsMagnetic Effects of CurrentActual
Two current carrying identical coils are kept as shown in figure. The magnetic field at centre ' O ' is ( N and R represent the number of turns and radius of each coil respectively, ₀= permeability of free space)
Options
- A₀ NI 2 R
- B₀ NI 2 R
- C₀ NI 2 2 R
- D₀ NI 2
Correct answer
B. ₀ NI 2 R
Step-by-step solution
The magnetic field at the center O results from the vector sum of fields produced by two perpendicular coils. Each coil contributes B = ₀ N I 2R at its center. With coils perpendicular, their fields are orthogonal. The net magnitude is B_ net = ( ₀ N I 2R )^2 + ( ₀ N I 2R )^2 = 2 ₀ N I 2R . Simplifying yields B_ net = ₀ N I 2 R . Final answer: ₀ N I 2 R