Two equal positive point charges are separated by distance 2a. The distance from the centre of the line joining them, on the equatorial line, where force on a test charge q₀ becomes maximum is a/√x. The value of x is ______. Image
Physics · Circular Motion
JEE Mains 1 February 2023 Shift 1 Morning Shift

Question

Two equal positive point charges are separated by distance 2a. The distance from the centre of the line joining them, on the equatorial line, where force on a test charge q₀ becomes maximum is a/√x. The value of x is ______. Image

Physics · Circular Motion

JEE Mains 1 February 2023 Shift 1 Morning Shift

G1 Physics · Accepted Answer

At distance x₀ on the perpendicular bisector, force magnitude is proportional to x₀/(x₀²+a²)^(3/2). Differentiating and setting derivative to zero gives a²−2x₀²=0. Hence x₀=a/√2, so x=2.