# Electric field and electric field lines

In this topic we will discuss about what is electric field and electric field lines , also electric field intensity at a point due to a point charge .

Electric field – Due to given  electric charge it is the  space around a charge particle in which electrostatic force can be experienced .

Electric field intensity –  Electric field intensity at a point is the force experienced at unit charge  placed at that point  , it is strength of electric field at that point .

Electric field   = F/q0

Electric field intensity due to a point charge –  Suppose a charge Q is placed at point O , we have to find the electric field intensity at point p which is r distance away from charge Q   .

Suppose a test charge q is placed at point p , then force acting at charge q due to Q is given as                                             F = KQq/r2    ,

therefore electric field E = F/q

so, E =( kQq/r2 )/q

E = kQ/r2

If we have to find the electric field at a point due to group of charges then we can write

Net electric field,  E = E1 + E2 +E3 ..………..

Electric field lines – It is the imaginary line the tangent at any point on this lines gives the direction of force at that point .

To watch the video on electric field and electric field lines visit on given link below-

Properties of Electric field lines

1. Electric field lines are continuous curve . They start from positive charge and end into negative charge . this is why electric field lines not form a closed loop . If there is a single charge then field lines start from the charge and goes into infinity .

2. Tangent to the electric field lines at any point gives the               direction of electric field intensity at that point .

3. No two field lines intersect each other . This is because at the point of intersection , there will be two direction of force at the same point which is not possible .

4. The electric field lines are always normal to the surface of a conductor .

5. Where field lines are denser the electric filed intensity is more and vice- versa .

To watch the video of properties of electric field lines click on given link below-

***So in the form of electric field lines electric field intensity is equal to the number of field lines crossing normally a unit area around that point .