Question

Two infinitely long straight parallel conductors carrying currents $I_1$ and $I_2$ are held at a distance d apart in vacuum. The force F on a length L of one of the conductors due to the other is _______.
Fill in the blank with the correct answer from the options given below

• A. proportional to L but independent of $I_1\times I_2$
• B. proportional to $I_1 × I_2$ but independent of length L
• C. proportional to $I_1 × I_2 × L$
• D. proportional to$\frac{L}{ I_1 × I_2}$

Answer 1

Answer: (C)

proportional to $I_1 × I_2 × L$

Answer 2

The force between two parallel current-carrying conductors is given by $F=\frac{μ0I_1I_2L}{2\pi d}$ , meaning the force is proportional to the product of the currents$I_1$ and $I_2$, the length of the conductor L, and inversely proportional to the distance d between them.