The electrical resistance of a wire varies as its length and inversely as the square of the diameter.
R = (k*L)/(d^2)
where k = proportionality constant
Since the two wires have the same material, their proportionality constant is same.
Equating that
(R1*d1^2)/L1 = (R2*d2^2)/L2
Given that R1 = 10 ohms, d1 = 1.2 mm or 0.0012 m, L1 = 18 m, d2 = 1.5 mm or 0.0015 m, L2 = 27 m, and R2 is unknown.
Therefore
[10*(0.0012^2)]/18 = [R2*(0.0015^2)]/27
R2 = 9.6 ohms
Move the 150 to the left to get x^2+5x-150=0
Then factor to (x+15)(x-10)=0
The roots are -15 and 10
The positive root is 10
The most important thing is the fact that you can get a chance to share
It can be many things such as,
420/2
630/3
840/4
