Chapter 21 potential 第八章静电场 To ensure U at a point, a reference potential energy should be chosen B=0,U 0 The U of charge g at arbitrary B point a= the work done by the fe during the move or/4g E charge g from a to infinity 试验电荷Q。在电场中某点的电势能,在数值上 就等于把它从该点移到零势能处静电场力所作的功 电势能的大小是相对的,电势能的差是绝对的Chapter 21 potential 第八章静电场 To ensure U at a point, a reference potential energy should be chosen:  0, UB The U of charge q at arbitrary point a = the work done by the during the move of charge q from a to infinity. Fe    AB A U q E l   0 d 试验电荷 在电场中某点的电势能，在数值上 就等于把它从该点移到零势能处静电场力所作的功. q0 电势能的大小是相对的，电势能的差是绝对的. E  0 q A B