Two long straight parallel wires, carrying (adjustable) currents `I_(1)` and `I_(2)` are kept at a distance d apart. If the force F between the two wires is taken as positive when the wire repel each other and negative when the wires attract each other, the graph showing the dependence of F, on the product `I_(1)I_(2)` would be:

Options

A.
B.
C.
D.

Answer

d

Explanation

Magnitude of force is proportional to the product of current, hence graphs will be linear. When product of currents is negative then it means currents are flowing along opposite directions and hence wires will repel each other so force acting between the wires become positive. When product of currents is positive then it means currents are flowing in the same direction and hence wires will attract each other and force is assumed as negative for the case of attraction. We can see that option (d) is correct