A uniform electric field E = 500 N C⁻¹ passes through a hemispherical surface of radius R = 1.2 m as shown in figure. The net electric flux (in S.I. units) through the hemispherical surface only is Nπ. Then find the value of N.

Question

G1 Physics · Accepted Answer

Step 1: Close the hemispherical surface with its circular base. The total flux of a uniform field through any closed surface is zero because no charge is enclosed. Step 2: Thus flux through the curved hemisphere is minus the flux through the base. Using the angle shown, |Φ|=EA cos53°=500×π(1.2)²×(3/5)=576π. Step 3: N=576.