Masses of three wires of copper are in the ratio of 1: 3: 5 and their lengths are in the ratio of 5: 3: 1 . The ratio of their electrical resistances is

Step-by-step solution

Given, m₁: m₂: m₃=1: 3: 5 and I₁: I₂: I₃=5: 3: 1 We know that, electrical resistance, R= l A and d= m V = m A l or A= m d l A m l ( density is same for the three wires) R₁: R₂: R₃= l₁ A₁ : I₂ A₂ : I₃ A₃ or R₁: R₂: R₃= l₁² m₁ : l₂² m₂ : l₃² m₃ = 25 1 : 9 3 : 1 5 R₁: R₂: R₃=125: 15: 1