Question

The force between two parallel wires carrying current has been used to define

• A. $ampere$
• B. $couloumb$
• C. $volt$
• D. $watt$

Answer 1

The correct option is A

$ampere$

Explanation for the correct answer:

1. The force acting between two parallel conductors can be determined by the equation $F=\frac{{\mu }_0{I}_1{I}_{2}l}{2\mathrm{\pi r}}N$Where $I_1$ and $I_2$are the currents in two wires, l is the length of the conductor and $r$ is the distance between two parallel wires.
2. If the parallel wires are separated by $1m$ each carrying a current of $1A$ , then $\frac{F}{l}=2\times {10}^{-7}N/m$
3. Thus, the definition of ampere can be defined as, one ampere is that current through each of the two parallel wires of infinite length, separated by $1m$ distance experiences a force of $2\times {10}^{-7}N$ on each conductor.

Hence, option A is the correct answer.