Question

When two parallel wires carry currents in the same direction,

• A. they attract each- other
• B. they repel each other
• C. magnetic forces on two wires are perpendicular to each other
• D. they do not experience any magnetic force

Answer 1

Answer: (A)

Force between two current carrying parallel conductor per unit length,
$F=\frac{{\mu }_0}{2}\frac{2L_1{L}_2}{r}$
According to question,
Current in two parallel wire is in same direction therefore they attract each-other