## Wednesday, November 21, 2012

### Electric Field Due To A Point Charge

Charge Q produces an electric field everywhere in the surrounding. When another charge q is brought at some point P, the field there acts on it and produces a force. The electric field produced by the charge Q at a point r is given as
where rˆ = r/r, is a unit vector from the origin to the point r. Thus, above equation specifies the value of the electric field for each value of the position vector r. We obtain the force F exerted by a charge Q on a charge q, as
It experiences a force F equal to the charge q multiplied by the electric field E at the location of q. Thus,
F(r) = q E(r). SI unit of electric field is give by N/C.
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Some of these questions which may be asked in your Board Examination 2012-2013

Q1: What is a charge?

Q2: What is the SI unit of Charge?

Q3: What is charge on a neutron?

Q4: what is the change on an electron?

Q5: Explain what is an fundamental electronic charge?

Q6: what is main cause of charging?

Q7: Electrostatic forces are much stronger than gravitational forces. Give one example.

Q8: What is the value of charge on an electron? is a charge less than this value possible?

Q9: What is charge on a photon?