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**fardeen_gen** The plastic rod of length $\displaystyle L$ in the diagram has non uniform linear charge density $\displaystyle \lambda = cx$ where c is a positive constant.

(a) With V = 0 at infinity, find the electric potential at point $\displaystyle P_2$ on the y-axis, at a distance y from one end of the rod.

(b) From that result, find the electric field component $\displaystyle E_y$ at $\displaystyle P_2$

(c) Why cannot the field component $\displaystyle E_x$ at $\displaystyle P_2$ be found using the result of (a)?