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. The electric potential at the point P (origin) as shown in the figure is
Options
- AV = a 4 π ε 0 l b b + l  
- BV = a 4 π ε 0 b l b + l  
- CV = a 4 π ε 0 b l  
- DV = a 4 π ε 0 l b  
Correct answer
A. V = a 4 π ε 0 l b b + l  
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 2 V = k a   1 b - 1 b + l V = a 4 π ε 0 l b b + l