Question

A 11.0 nC charge is at x = 0cm and a -1.3 nC charge is at x = 6 cm .

At what point or points on the x-axis is the electric potential zero?

Express your answer using two significant figures. If there is more than one answer, give each answer separated by a comma.

Answer 1

There are two points where net potential is zero

When the point is in between

Let us consider that the point is to the right side at a distance d from 11 nC

k q1 / d = k q2 / ( x - d)

6 / d - 1 = 1.3 / 11

d = 5.37 cm

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If the point is to the right of - 1.3 nC

Let us consider that the point is to the right of 1.3 nC at a distanced from it

k * 11 / ( 6 + d) = k 1.3 / d

6/d + 1 = 11/1.3

d = 0.80 cm

X co ordinate = 6 + d = 6.80 cm

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