Question

2.Why do we need the concepts Force and Electric field? What are they?

Why electric field lines never intersect?

What are electric dipole and electric dipole moment?

Define electric potential energy of an electric dipole.

What are stable and unstable equilibrium positions for an electric dipole?.

Answer 1

Solution:

Let's see each question one by one

a) We need concepts like force and electric field because that tells us how the charge is behaving in the presence of another charged or uncharged body, These concepts help us to know about the movement of charges, and like we study electric field when we study lightning and how a metal box can save us from lightning as electric field inside conductor is zero, and there are lots of things that can be explained with the help of electric force and electric field.  

Force : It is the force exprerienced by object due to charge can be repulsion or attraction.

Electric field: It is the field or area around the charge in which electric force can be experienced.

b)  Acutally When we draw tangent to the electrice field lines it give us the direction of electrice field at that point Now if electric field lines intersect then at the point of intersection we can draw two tangents and that implies that we will have two directions of electric field at same point which is not possible so electric field lines never intersect.

c) In a simple way electric potential energy is defined as the amount of workdone needed to bring electric dipole from one angle to another as it is U = -PE(cos A - cos B)

d) When dipole and electric field are aligned anti parallel then it is said to be in unstable equilibrium

and When dipole and electric field are aligned parallel then it is said to be in stable equilibrium.

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