Question

Please answer the 3 question with full explanation! Answer is option D. Spams will be reported!​

Answer 1

Explanation:

Let a slice of a disc of thickness dr at a distance r from the centre.

area of the slice is given by 2πrdr

let dq be the charge associated with that slice,then surface charge density = dq / area

= dq / 2πrdr

dq = 2πrdr surface charge density

dq = 2πr dr x Sigma0 R/r

dq = 2π dr Sigma0 R

ON ITEGRATING OVER THE LIMIT 0 to R

Q = 2π Sigma0 R²