Two long conductors, separated by a distance carry current and in the same direction. They exert a force on each other. Now the current in one of them increased to two times and its direction reversed. The distance is also increased to . The new value of the force between them is:
- A
- B
- C
- D
Solution & Step-by-step Explanation
The force per unit length between two parallel wires is:
Initially, the force is attractive ().Case 2: (reversed and doubled), .
The negative sign indicates the force is now repulsive.
Initially, the force is attractive ().Case 2: (reversed and doubled), .
The negative sign indicates the force is now repulsive.