Can electric fields be negative?

The space around a charge is always under stress, meaning it can exert a force on another charge placed within it. This region is known as the electric field (also called the dielectric field or electrostatic field). The stress in this space is visualized using lines of force, and the electric field itself is a vector quantity, having both magnitude and direction.

The electric field at a point is defined as the force experienced by a charge divided by the magnitude of the charge. Here, the magnitude of the charge is always considered positive, even if the charge itself is negative. Therefore, the magnitude of the electric field can never be negative, though its direction can vary.

• If a negative charge (like an electron) is placed in an electric field, it experiences a force opposite to the field direction.
• If a positive charge is placed in the field, it experiences a force along the field direction.

Note:

• The magnitude of the electric field can be calculated using Coulomb’s law.
• For a unit stationary point charge, the derivation of Coulomb’s law is similar to the derivation using Gauss’s law.
• When two charged bodies are placed near each other, they experience a mechanical force, which is also a vector quantity.