For all problems, please show explicitly the work that you have done to arrive at your answer. It is helpful to note the property you have used to arrive at your answer, and to include such equation before inserting numerical values. Remember to include units & to mind your significant figures! You may find it helpful to draw a diagram, but this is not required.

4. Fig. 3 shows a radial arm of unit length that moves through angle 0 = 3x /4 to take point charge Q from point A to point B. What is the potential difference of such a movement under uniform electric field E of magnitude 123 V/m? Hint: B this problem is quick if you can calculate the distance between A and B directly, although maybe this is not the easiest method. Remember: the answer is path independent. A E Fig. 3. Radial arm setup for problem 4