In the figure below, determine the point (other than infinity) at which the tota
ID: 1628294 • Letter: I
Question
In the figure below, determine the point (other than infinity) at which the total electric field is zero. 1.82 m to the left of -2.5 times 10^-6 C charge Three identical charges (q = -7.4 mu C) lie along a circle of radius 2.5 m at angles of 30 degree, 150 degree, and 270 degree, as shown in the figure below. What is the resultant field at the center of the circle? Four closed surfaces, S_1 through S_4, together with the charges -2Q, Q, and -Q are sketched in the figure below. (The colored lines are the intersections of the surfaces with the page.) Find the electric flux through each surface. (Use the following as necessary: epsilon _0 and Q.) Phi _S1 Phi _S2 Phi _S3 Phi _S4Explanation / Answer
we know that direction of electric field is toward negative charge and away from positive charge, so in this given diagram, electric field can only be zero towards left of negative charge
Suppose at distance d from negative charge electric field is zero.
then
Electric field = k*Q/R^2
Enet = E+ - E- = 0
kq1/r1^2 = kq2/r2^2
r1 = 1 + d
r2 = d
6/(1+d)^2 = 2.5/(d^2)
Solving above equation
6*d^2 = 2.5(d^2 + 1 + 2d)
3.5*d^2 - 5d - 2.5 = 0
d = [5 +/- sqrt (25 + 4*3.5*2.5)]/(2*3.5)
d = 1.82 m to the left of -2.5uC charge