Question

Three charged cylindrical sheets are present in three spaces with σ = 5 at R = 2m, σ = -2 at R = 4m and σ = -3 at R = 5m. Find the flux density at R = 3m.

(a) 3

(b) 10/3

(c) 11/3

(d) 4

I had been asked this question in class test.

I need to ask this question from Applications of Gauss Law in chapter Electrostatic Fields of Electromagnetic Theory

Answer 1

The correct answer is (b) 10/3

The explanation: The radius is 3m, hence it will enclose one Gaussian cylinder of R = 2m.

By Gauss law, ψ = Q

D(2πRL) = σ(2πRL), D(2π X 3) = σ(2π X 2), Thus D = 10/3 units.