3. A thin rod of length l lines on the y axis with one end on the origin, carrying a non-uniform line density given by λ=λ₀y/l, (a)Calculate the potential at point P (See Figure 2) on the x axis, with a distance x from the origin. (7)_______ (b) Integrate the charge density to find the total charge on the rod. (8)_______ (c) Find the result that this expression reduce to an expected result when x ＞＞ l. (9)_______ (d) Find the magnitude of field component Ex at P: (10)_______. [Note that (1+x)ⁿ ≈ 1 + nx, for x ＜＜ 1.]