A non-conducting disc of radius R carries a surface charge density σ = 0.5 r μC/m2 on one face. Calculate the total charge on the disc in terms of R?

Question

A non-conducting disc of radius R carries a surface charge density

σ = 0.5 r μC/m2 on one face.

Calculate the total charge on the disc in terms of R?

Answer 1

Q = Int (σdA) = Int from 0 to R( (.5r) (2πrdr)) in microC (Area element is annular region of thickness dr)

Q = Int from r= 0 to R of (πr²dr) in microC

Good luck!