Physics and Chemistry Departmen Milwaukee School of Engineering 3/24/2017 Test#1
ID: 3164182 • Letter: P
Question
Physics and Chemistry Departmen Milwaukee School of Engineering 3/24/2017 Test#1 Spring 2017 PH 2021-71 Name Q3) Two point charges: Q1 3.0 nc is located at x -4.0um and Q2 3.0 nc is located at point x 1.0 um and y 2.0 pm, as shown in the figure. (a) What is the electric dipole moment of this pair -3.0 nC of charges (in unit vector notations i, j,k)? Q2- 3.0 If this dipole is placed in a region of space at which the electric potential is given by: b) Determine the electric field vector, E (in unit vector notations i, j,k) c) What is the net force acting of the dipole?Explanation / Answer
(c) Electric field is -60 i - 80 j + 40 k, which turns out to be uniform. So the dipole will experience no net force, only net torque. Note that dipole interacts with the gradiant of electric field, i.e. it will experience a net force only if electric field is nonuniform in space.