Hi,

I need help using a formula to find the length of an electrical conductor.

(A) The cross sectional area of the conductor is 2.5mm2 which I have been told : 2.5 x 10^-6 (power of minus 6).

(R) The resistance is 0.86 (in ohms).

(P) The resistivity of the conductor is 17.24 nanohm metres which is : 17.24 x 10^-9 (power of minus 9).

(L) The length is unknown.

The formula was R: PL/A, now that length is unknown I believe the formula changes to L: RA/P?

So I came up with 0.86 x (2.5 x 10^-6) / 17.24 x 10^-9

Which gives me 1.25 (this ain't the right answer), did I go wrong in formula transposing or something?

Thanks