Letter O

Ohm The basic unit of resistance, reactance and impedance. The
symbol for the ohm is “W”, the Greek letter omega.

Ohmmeter A meter designed to measure resistance.


Ohm’s Law
A law that states that the current in a circuit is directly
proportional to the voltage and inversely proportional to the
resistance.

Open Drip Proof (ODP)
A motor enclosure type that permits air flow through the motor,
but is designed to prevent liquids or solids falling from above
at angles up to 15 degrees from the vertical from entering the
motor.

Open-Loop Control A control technique that does not use a feedback signal.