Question

two long parallel wires carrt currents in the same direction. what is the nature of the force between the wires?

a) attractive

b) repulsive

c)there is no force between wires

d) there will be a force only if the currents are ac currents not dc currents

Please explain

Answer 1

a) attractive

By second right hand rule . Since we have two parallel wires with equal current going the same direction, that vector represents each of the wires velocity vectors.

By pointing our right thumb in this direction and using our pointer finger to represent the magnetic field (pointing back toward ourselves), at any point, the Force of the wire will be represented by our middle finger.

Thinking of this for both wires, the force vectors are pointing towards each other, resulting in an attractive relationship.