Question

Two parallel conductors carrying unequal currents in the same direction ................

• A. neither attract nor repel each other
• B. repel each other
• C. attract each other
• D. will have rotational motion

Answer 1

Answer: (C)

Two wires 1 and 2 carrying currents $i_1$, and $i_2$ respectively are shown in the figure given below,

Force on wire 2 -due to $B$, (field of wire 1 ) is given by
$F_2=i_{2}l{B}_1$
Using right hand screw rule, direction of $F_2$ would be towards wire 1 .
Similarly, force on wire due to $B_2$ (field of wire 2)
$F_1={\dot{i}}_1{B}_2$
Again, by using right hand screw rule,
direction of $F_1$ would be towards wire 2 .
If two parallel conductors carry (equal or unequal) current in the same direction, they will exerted force towards each other i.e., they will be attract each other.