Question

$P$ , $Q$ and $R$ are long straight wires in air, carrying currents as shown. The force on $Q$ is directed

• A. to the left
• B. to the right
• C. perpendicular to the plane of the diagram
• D. along the current in $Q$

Answer 1

Answer: (A)

Since the magnetic field at $Q$ by $P$ and $R$ is inward, therefore, both due to $20A$ $\left(P\right)$ as well as $60A$ $\left(R\right)$ , the force on $Q$ is towards left.