This document provides information on different types of induction motor rotors including deep bar cage rotors, double cage rotors, and wound or slip ring rotors. It explains that deep bar cage rotors have higher starting torque than normal cage rotors due to their increased resistivity. Double cage rotors have an outer cage made of high resistivity material and an inner copper cage, allowing for high starting torque from the outer cage and good efficiency from the inner cage at normal speeds. Slip ring motors have a wound rotor connected to slip rings, permitting external resistors to be added to the rotor circuit to control speed.