Point charges q1 = +2.00 mu C and q2 = -2.00 mu C are placed at adjacent corners
ID: 1641160 • Letter: P
Question
Point charges q1 = +2.00 mu C and q2 = -2.00 mu C are placed at adjacent corners of a square for which the length of each side is 3.00 cm. Point a is at the square and point b is at the empty comer closest to q2. Take the electric potential to be zero at a distance far from both charges. (a) What is the electric potential at point a due to q1 and q2? (b) What is the electric potential at point b? (c) A point charge q_3 = -5.00 mu C moves from point a to point b. How much work is done on q_3 by the electric forces exerted by q_1 and q_2? Is this work positive or negative?Explanation / Answer
Let s =3cm be the side of the square
and d be the diameter of the square, d=1.414s
a.) Potential at a= kq1/(d/2) +kq2/(d/2)
=2k (q1+q2)/d
=0 V
B.) potential at b =kq1/d + kq2/s
= k((q1/1.414)+q2)/s
=- 9x109-6x2x(1-(1/1.414))/0.03
=-17567.8529V
C.)work done = Q3 (vb-va)
= 5x10-6x(-17567.8529-0)j
=0.878joules