The thin glass rod of length \(\ell\) in Figure P23.57 has a linear charge density that starts out as zero at the left end of the rod and increases linearly from left to right. The positive charge on the rod is \(q_{\text {rod }}\).

(a) What is the electric field along the rod's axis at position P, which lies a distance \(d\) from the right end of the rod? 

\((b)\) What is the approximate expression for the magnitude of the electric field at distances \(d \gg \ell\)-that is, far enough away to make the rod look small?

Data from Figure P23.57

Transcribed Image Text:

Figure P23.57 +++++++ +++++++ d P x