A uniformly charged conducting sphere of 2.4 m diameter has a surface charge density of 80.0 μC/m2. (a) Find the charge on the sphere. (b) What is the total electric flux leaving the surface of the sphere?
Given: radius of sphere, r = 1.2 m
Surface charge density, σ = 80.0 μC/m2
a) Let charge on sphere = q
We understand that,
Total charge, Q = Surface charge density × surface area.
Surface area of sphere, S = 4πr2
S = 18.08 m2
Q = 80 × 10-6Cm-2 × 18.08m-2
⇒ Q = 1.447 × 10-3C
b) Let total electric flux leaving the surface of sphere = 
We know that,
Flux, Φ = q/ε0 …(1)
Where, Q = net charged.
ε0 = permittivity of free space
ε0 = 8.85 × 10-12N-1 m-2C2
By, plugging the values of q and ε0 in equation (1), we get,
⇒ 
⇒ Φ = 1.63 × 108 Nm2C-1
The total flux through the sphere is 1.63 × 108 Nm2C-1 .