NTA Abhyas JEE Main2020PhysicsElectrostaticsPractice
A rod of length l is placed along x -axis. One of its ends is at the origin. The rod has a non-uniform charge density λ = a x , a being a positive constant. Electric potential at P as shown in the figure is
Options
- Aa 4 π ε 0 ln b + l b
- Ba 4 π ε 0 ln l b
- Ca 4 π ε 0 ln b l
- Dzero
Correct answer
A. a 4 π ε 0 ln b + l b
Step-by-step solution
V   = ∫ b b + l k d q x = ∫ b b + l k λ d x x =   k a   ∫ b b + l d x x V = K a   ln b + l b   V   = a 4 π ε 0 ln b + l b