Question

Difference between source charge and test charge

Answer 1

Point charge: Any charge whether positive or negative, whose electric field is to be found at a particular distance(point) is called point charge.

Test charge: Any charge whose magnitude is very small, in fact negligible, as compared to that of the point charge, and which does not affect the electric field of the point charge, whose magnitude is to be found out, is called test charge.

Answer 2

Test charge-The charge which tests effect of source charge.A test charge is a point charge that does not disturb any field.It is a small electro positive charge used for experiments.

In case of test charge,they can be positive because it is higher potential and In case of negative charge,they are lower potential.The test charge must be small in magnitude relative to magnitude of charge producing the fields and be positive.It is also hypothetical charge located at a single point in space.

Source charge-The charge which produce electric field and It is a large charge through which electric fields flow.It may be a point charges,or a continuous distribution of charges.Here the range of any source charge around space Is infinity,that is Electric field extends till infinity.