Question

The capacitance per unit length of a capacitor consisting of two long concentric cylinder with radii a and b, (b > a) is C = (2πε₀)/(ln(b/a)). If a = 10 ± 1 mm and b = 20 ± 1 mm, with what relative precision is C measured?

Answer 1

Substituting a = 10 mm, b = 20 mm, σ_a = 1 mm and σ_b = 1 mm, σ_c/c = 0.16