Question

A cylinder with circular cross-section is the appropriate Gaussian surface to use when analyzing all of the following charge distributions EXCEPT

• A. A long, straight charged wire
• B. A point charge
• C. The inside of a uniformly charged, insulated rod
• D. The inside of a charged, insulated rod whose charge density varies with radius
• E. A large, uniformly charged plane

Answer 1

The correct option is B A point charge

The electric field due to a point charge points radially outwards (or inwards) in all direction, thus an appropriate Gaussian surface for a point charge is a sphere but cannot be a cylinder.

Thus option B is correct.