Question

Points A and B are 0.10 􀀄 apart. A point charge of +3.0 × 10^-9C is placed at A and a point charge of

−1.0 × 10^-9C is placed at B.

i) X is a point on the straight line through A and B, between A and B, where the electric potential is zero.

Calculate the distance AX.

ii) Show on a diagram the appropriate position of a point, Y, on the straight line through A and B where the field strength is zero.

Answer 1

Answer

1) using direct short formula to calculate distance AX from point charge 3nC

$x=\frac{\sqrt{q}}{\sqrt{q}+\sqrt{q'}}r=\frac{\sqrt{3}}{\sqrt{3}+\sqrt{1}}(10cm)$

$x=6cm$ from point charge 3nC or called AX.

2) diagram can be shown as below