Consider the special case where Q 1 , Q 3 greater than zero and Q 2 = -Q 1 . Whi
ID: 1579538 • Letter: C
Question
Consider the special case where Q1, Q3 greater than zero and Q2 = -Q1. Which of the following statements are true? (Choose all correct answers e.g. ABD, CDFG).
A) The electric potential at any point along the y-axis is positive.
B) The force on Q3 due to the other two charges is zero.
C) If Q3 is released from rest, it will initially accelerate to the right.
D) The electric potential at the origin equals Q3/(4*pi*epsilon0*d).
E) The work required to move Q3 from its present position to the origin is zero.
F) The external work done to bring these charges to this configuration (from infinity) was positive.
G) The electric field at the origin points in the positive y direction, away from Q3.
Explanation / Answer
A) as potential a scalar quantity the potential due to q1 & q2 gets cancelled out.
C)yes as the components along the y axis get cancelled and along +ve x get added.
D)potential due to q1 and q2 gets cancelled out.
E) yes as W = F.D where the force is perpendicular to distance moved so cos 90 makes the work done zero.
F)Yes, as the system is not in stable equilibrium.