Question

Problem 3: Two positive point charges, each of charge Q > 0, are located at the two upper corners of a square; and two negative point charges, each of charge - Q<0, are located at the two lower corners of that square, in the x-y-plane, as shown in the figure below. The points R, S, T, and U are the mid-points of the edges and M is the center of the square. Two edges of the square are parellel to the x-axis, and two edges are parallel to the y-axis, with 2- and y-axis oriented as shown below. The total electric field, generated at these five points by the four charges, is denoted by Er = (Erz, Ery), Es = (Es... Es,y), Ēr = (Era, Ers), Ev = (Eu,z, Evy) and ĒM = (EMX, Emy), respectively. Which of the following is true? Q O (A) The Ē-field vanishes at M, i.e., ĒM = 0. (B) The E-field y-component at R is positive, i.e., Ery > 0. (C) The Ē-field y-component vanishes at S, i.e., Esy = 0. (D) The E-field 2-component vanishes at T', i.e., ET: = 0). (E) The E-field y-component at U is positive, i.e., Er., > 0.

Answer 1

o --.- (1) the Efield vanishes at M re DT Eml=0 (Fake) Ó (V) Eryzo (false) O Esy =o (false) TO ET,x=0 (True) W @ ET, y 20 (7)