roto - sear
- rotor
- rotor angle measurement
- rotor banding
- rotor circuit
- rotor coil
- rotor core
- rotor current
- rotor displacement angle
- rotor displacemet angle measurement
- rotor earth fault protection
- rotor end bell
- rotor end winding ring
- rotor field
- rotor pack
- rotor resistance starter
- rotor resistance starting
- rotor rheostat
- rotor slot
- rotor winding
- rough approximation
- rough reading scale
- rough service lamp
- rough surface
- rough vacuum
- roughness
- round cable
- round chart
- round rotor motor
- round the clock service
- round trip
- round trip loss
- round trip time
- rousseau diagram
- route
- route inspection
- route locking
- route planning
- router
- routh coefficient
- routh stability criterion
