In chlorobenzene, the electrophilic substitution takes place at o- and p-positions.

Yes, that's correct. In chlorobenzene, the electrophilic substitution primarily occurs at the ortho (o-) and para (p-) positions. This is due to the fact that the chlorine atom is ortho, para-directing because of the resonance effect. The lone pair of electrons on the chlorine atom can be delocalized into the benzene ring, making the ortho and para positions more electron-rich and thus more attractive to electrophiles. However, the reaction rate is slower than that of benzene due to the deactivating nature of the chlorine substituent.