Practice portal › Electric Charge and Properties › Field of Spheres, Shells and Cylinders

For a uniformly charged thin spherical shell, the electric field at any point outside the shell is

Asked in GSEB Board July 2023 · Shell and uniform solid sphere

• (1) as if the total charge were concentrated at the centre
• (2) infinite
• (3) independent of the charge
• (4) zero

Step-by-step solution

Why the other options are wrong

• (2) The field outside is finite everywhere: E=1/(4πε₀)Q/(r²) with r never smaller than the radius R, so it cannot blow up.
• (3) Gauss's law ties the field to the enclosed charge, E×4π r²=Q/(ε₀): doubling Q doubles E.
• (4) Zero is the field inside the shell, where a Gaussian sphere encloses no charge. Outside, the Gaussian sphere encloses the whole charge Q.

Reading this solution needs no sign-in. You only sign in to practise against the clock and keep your progress.