To determine the work done in moving a charge from point B to point A , we use the formula: Wext=q∆V Where: q is the charge being moved, given as 5 mC or 5×10−3C. ∆V is the change in electric potential between the two points: Vf−Vi. Given: Potential at point A, VA=−3V Potential at point B,VB=5V Substitute these values into the formula: ‌W‌ext ‌=5×10−3(VA−VB) ‌=5×10−3(−3−5) ‌=5×10−3×(−8) ‌=−40×10−3J ‌=−0.04J Thus, the work done in carrying the charge from point B to point A is -0.04 J .