Three long, straight and parallel wires carrying currents are arranged as shown in figure. The force experienced by 10 cm length of wire Q is

Question

G1 Physics · Accepted Answer

Between parallel currents, F/L=μ₀I₁I₂/(2πd), attractive for same direction and repulsive for opposite direction. Summing the forces on the 10 cm portion of Q due to P and R gives 1.4×10⁻⁴ N to the right. Hence A.