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 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 –
- 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 .