A liquid resistor consists of two concentric metal cylinders of diameters D = 35 cm and d = 20 cm respectively with water of specific resistance ρ = 8000 Ω cm between them. The length of both cylinders is 60 cm. Calculate the resistance of the liquid resistor.
r1 = 10 cm ; r2 = 17.5 cm;
log10 (1.75) = 0.243
ρ = 8 × 103 Ω − cm; l = 60 cm.
Resistance of the liquid resistor
R = (2.3 x 8 x 103)/(2π x 60) x 0.243 = 11.85Ω
