Question

An unknown positive charge produces an electric field with a magnitude of 0.005 N/C. If the unknown charge is made negative, how does the electric field change?

An negative test charge is placed next to each charge. What will happen to the test charge in each case. Why?

Answer 1

---- For the positive charge, electric field is directed away from the charge. When it is replaced with negative charge, then the direction of electric field reverse and it point inward. It helps in deciding how positive test charge will move in the given electric field.

---- When a negative test charge is placed in the vicinity of positive charge, then due to attraction, it moves towards the positive charge. It direction can be determined from from the electric field direction.

---- When a negative test charge is placed in the vicinity of negative charge, then due to repulsion, it moves away from the negative charge. It direction can be determined from from the electric field direction.