Question

Suppose two long straight wires run perpendicular to one another without touching. Does one exert a net force on the other? If so, what is its direction? Does one exert a net torque on the other? If so, what is its direction? Justify your responses by using the right hand rules.

Short answer

Forces and Torque are equal to zero.

Step-by-step solution

Definition of Force and torque.

Force is defined as an external agent capable of changing the state of rest or motion of a particular body. It has a magnitude and a direction.

Torque is the measure of the force that can cause an object to rotate about an axis.

Explanation for the net torque and net force.

Since electric force between two wires with the current flowing in the same direction is attractive, and if the currents are in the opposite direction, the force is repulsive. Therefore, we can conclude that the force on the two perpendicular wires will be equal to zero and since the situation is symmetrical, there will be no torque as well.

We can confirm this using the right-hand rule because we cannot position our fingers facing the same direction and still get an actual result that is facing somewhere in the third direction.

Therefore, the forces and torque are equal to zero.