when a unit charge or point charge is placed in the electric field of another charged particle, it will experience a force.the direction of this force can be represented by the imaginary lines. these imaginary lines are called electric lines of force. electric lines of force are also called as electric field lines. the concept of electric lines of forces was introduced by michael faraday in 1837.
properties- 1. they start from a positive charge and ends on a negative charge.2. they always enter or leave the charged surface normally. 3.they can never intersect each other. 4. they cannot pass through a conductor. 5. when two opposite charges are placed close to each other, the electric lines of force present between them will become shorten in length. 6. when two like charges are placed closer to each other, the electric lines of force present between them will become enlarged in length.