Question: A uniformly charged sphere of radius R has a total charge Q. What is the electric field at a point outside the sphere (r > R)?

Options:

1. 0
2. Q/(4πε₀r²)
3. Q/(4πε₀R²)
4. Q/(4πε₀R)

Correct Answer: Q/(4πε₀r²)

Solution:

For a uniformly charged sphere, the electric field outside the sphere behaves as if all the charge were concentrated at the center, thus E = Q/(4πε₀r²).