Two point charges are placed along a horizontal axis with the following values and positions: +3.8 µC at x = 0 cm and −7.6 µC at x = 20 cm.At what point along the x axis is the electric field zero?
A)10 cm
B)8 cm
C)-5 cm
D)-48 cm
E)-68 cm

Question

Two point charges are placed along a horizontal axis with the following values and positions: +3.8 µC at x = 0 cm and −7.6 µC at x = 20 cm.At what point along the x axis is the electric field zero?​
A)10 cm
B)8 cm
C)-5 cm
D)-48 cm
E)​-68 cm

Quizplus · Accepted Answer

The electric field is zero at a point where the magnitudes of the electric fields due to each charge are equal. Since the negative charge is larger in magnitude, the point where the electric field is zero must be to the left of the positive charge (x = 0 cm). By setting up the equation for the electric fields due to each charge being equal and solving for the position, we find that this point is to the left of the positive charge, resulting in a negative x-value, which matches option D, -48 cm.

Two Point Charges Are Placed Along a Horizontal Axis with the Following