(a) Electric flux, ϕ=−1×103Nm2/C
Radius of the Gaussian surface,
r=10.0cm
Electric flux coming out through a surface depends on the net charge enclosed inside a body. It does not depend on the size of the body. If the radius of the Gaussian surface is doubled, then the flux passing through the surface remains the same i.e., - 103Nm2/C.
(b) q=ϵ0Φ=8.85×10−12×−1×103C=−8.85nC