Question

Two long parallel wires carry currents \( I_1 \) and \( I_2 \) (\( I_1 > I_2 \)). When currents are flowing in the same direction, the magnetic field at a point midway between the wires is \( 6 \times 10^{-6} \, \text{T} \). If the direction of \( I_2 \) is reversed, the field at the midpoint becomes \( 3 \times 10^{-5} \, \text{T} \). The ratio \( I_1 : I_2 \) is

• A. 3 : 2
• B. 2 : 3
• C. 3 : 5
• D. 6 : 7

Hint:

When two currents flow in the same direction, their magnetic fields at a midpoint add up. When the currents flow in opposite directions, their magnetic fields subtract from each other.

Answer 1

The Correct Option is B