JEE MainPhysicsElectrostatics
A short electric dipole is placed at the origin. The electrostatic potential V is measured at various distances r on its axial line. If a graph is plotted with (V) on the y-axis and (r) on the x-axis, the slope of the resulting straight line is :
Options
- A-1
- B-3
- C-2
- D2
Correct answer
C. -2
Step-by-step solution
The electrostatic potential V at a distance r on the axial line of a short electric dipole is given by: V = 1 4 ₀ p r^2 Let C = p 4 ₀ , which is a constant. Then, V = C r^2 Taking the natural logarithm on both sides, we get: (V) = (C) - 2 (r) Comparing this with the equation of a straight line y = mx + c , where y = (V) and x = (r) , the slope m is -2 . Answer: -2