Electric Field

An electric field is a region where electrical force is being experienced due to the presence of the physical agency charge.

The charge that is used to measure the electric field strength is referred to as a test charge
since it is used to test the field strength. A test charge is a charge with a magnitude so small that placing it at a point has a negligible effect on the field around the point. A positive test charge is a unit positive charge which is used to determine the strength and direction of an electric field.

With the aid of a test charge, we can map out an electric field using a number of lines called the electric line of force .

An electric line of force is an imaginary continuous line or curve drawn in an electric field such that tangent to it at any point gives the direction of the electric force at that point. The direction of a line of force is the path or direction along which a small free positive charge will follow if placed in a field.