A rod of length L lies along the x-axis with its left end at the origin. It has a non-uniform charge density `lamda=alphax`, where a is a positive constant.
(a) What are the units of `alpha`?
(b) Calculate the electric potential at point A where `x = - d` .

Options

A. `(1)/(4pi epsi_(0)) a[l+b (1+l//b)]`
B. `(1)/(4pi epsi_(0)) a[1-b log_(e) (1+l//b)]`
C. `(1)/(4piepsi_(0)) a[l+b log_(e) (1+l//b)]`
D. `(1)/(4piepsi_(0)) a[l-b(1+l//b)]`

Answer

B

Explanation

`V_P =in dV = int (kdq)/(x+b) =underset(0)overset(1)int (kaxdx)/(x+b)`