Two parallel wires carry currents of 20 A and 40 A in opposite directions. Another wire carrying a current antiparallel to 20 A is placed midway between the two wires. The magnetic force on its will be
The third wire is carrying a current 20A antiparallel to the previously set 20A current wire. So these wires will repel each other. As the 40A wire is carrying a current in the opposite direction to the previously set 20A wire, the newly set 20A wire will be having the same current direction to it. So they will attract. So the newly set wire in the midway will move towards the 40A wire.
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