The electric-field magnitude at the centre of a uniformly charged hemispherical shell is E₀. Two portions are cut from the hemisphere as shown. If α = β = π/3 and the field due to the remaining portion is E = E₀/n, find n.

The electric-field magnitude at the centre of a uniformly charged hemispherical shell is E₀. Two portions are cut from the hemisphere as shown. If α = β = π/3 and the field due to the remaining portion is E = E₀/n, find n.
