Question

Find the true statement.

(a) The force between two parallel current carrying wires is independent of the radii of the wires

(b) The force between two parallel current carrying wires is independent of the length of the wires

(c) The force between two parallel current carrying wires is independent of the magnitude of currents

(d) The force between two parallel current carrying wires is independent of their distance of separation

The question was asked by my college professor while I was bunking the class.

Query is from Ampere’s Circuital Law topic in division Moving Charges and Magnetism of Physics – Class 12

Answer 1

Correct answer is (a) The force between two parallel current carrying wires is independent of the radii of the wires

For explanation I would say: The force between two parallel current carrying wires is independent of the radii of the wires.

From Ampere’s circuital law, the magnitude of the field due to the first conductor can be given by:

B = \(\frac {\mu_o I_1}{2\pi d}\)

The force between the parallel plates is given by:

B= \([\frac {\mu_o I_1 I_2}{2\pi d}] \) L

From this equation, we understand that the force between the parallel current carrying wires does not depend on the ‘radii’.