Question

Two charges $+Q$ and $-2Q$ are located at points $A$ and $B$ on a horizontal line as shown below:
The electric field is zero at a point which is located at a finite distance:

• A. On the perpendicular bisector of $AB$.
• B. Left of $A$ on the line
• C. Between $A$ and $B$ on the line
• D. Right of $B$ on the line

Answer 1

The correct option is B Left of $A$ on the line

The electric field is zero at a point where Electric field due to points A and B are opposite in direction and equal in magnitude, which is only possible on the left side of A on the line. On the right of B on the line, fields due to A and B can not be equal and between A and B on the line, fields are in same direction. Therefore, Option 'B' is correct.