Question

The equipotential surface is:

• A. A plane for a point charge
• B. Spherical for a dipole
• C. Cylindrical for a dipole
• D. Spherical for a point charge
• E. Cylindrical for a point charge

Hint:

For a point charge, the equipotential surfaces are spherical, centered at the charge. For more complex charge distributions like dipoles, the equipotential surfaces are not spherical.

Answer 1

The Correct Option is D

An equipotential surface is a surface on which the electric potential is constant at all points.

1. For a point charge:

The electric potential is given by:

\[ V = \frac{kQ}{r} \]

where:

• \( k \) is Coulomb's constant.
• \( Q \) is the charge.
• \( r \) is the distance from the point charge.

Since this potential depends only on the distance from the charge, the equipotential surfaces for a point charge are spherical. These surfaces are concentric spheres with the point charge at the center.

2. For a dipole:

The electric potential at a point is a function of both distance and angle from the dipole. At large distances, the equipotential surfaces are approximately spherical. However, at small distances, the equipotential surfaces take a more complicated shape and are not purely spherical.

Therefore, the correct answer is that the equipotential surface is spherical for a point charge.

Thus, the correct answer is:

\[ \boxed{\text{D) Spherical for a point charge}} \]