Q: In a system of charges along the x-axis, the charges q₂, -q, and q₂ are placed at specific points. What is the resultant potential at point A, located at a distance y from charge q (where r << y)?  

To calculate the resultant potential at point A, we need to consider the electric potentials contributed by each charge at that point. The potential at point A due to the charge q₂ positioned at x = y - r is given by qr²/(4πε₀(y - r)³). This can be obtained using the formula for electric potential due to a point charge. The potential at point A due to the charge -q positioned at x = r is -q/(4πε₀r). The negative sign arises because the charge is negative. The potential at point A due to the charge q₂ positioned at x = y + r is qr²/(4πε₀(y + r)³).] Taking into account all three charges, the resultant potential at point A is obtained by summing up these individual potentials. Hence, the correct answer is option C) V = qr²/(24πε₀y³).