About the work done in moving a charge in an electric field

[bsmm11]

An external force moved a positive test charge from A to B where B is closer to the centre of the field. Therefore, the force exerted by the field is from A to B.
The textbook is saying the work done is negative. But the external force moved the charge against the electric field strength as if a person moves a box to a higher place against the gravitational field strength, so wouldn't the work done by the external force is positive? Or is the force textbook is saying is the force by the field? If that is the case, when we are dealing with the work done in moving something in the field, is it usually work done by the field, not the external force?

 

[Vailanor]

The work done is indeed positive when an external force moves a test charge from A to B. The textbook is referring to the work done by the electric field, which is negative because it opposes the motion of the test charge. In general, when dealing with work done in moving something in a field, it's usually the work done by the field, not the external force.