As shown in the figure 20 A, 40 A and 60 A currents are passing through very long straight wires P, Q and R respectively in the direction shown by the arrows. In this condition the direction of the resultant force on wire Q is .

Question

Accepted Answer

(1) towards left of wire Q. Given: P carries 20 A and Q 40 A in the same direction, while R carries 60 A in the opposite direction (the arrows in the figure). Idea: parallel currents attract, antiparallel currents repel, and each force acts along the perpendicular from the neighbouring wire to Q. P and Q are parallel currents, so P attracts Q: Q is pulled towards P, that is to the left. Q and R are antiparallel, so R repels Q: Q is pushed away from R, which is again to the left. Both contributions point the same way, so the resultant force on Q is towards the left of Q — and no separations are needed to settle it.

As shown in the figure 20 A, 40 A and 60 A currents are passing through very long straight wires P, Q and R respectively in the direction shown by the arrows. In this condition the direction of the resultant force on wire Q is ______.

Step-by-step solution

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