The primary function of an optical encoder is to provide position information.

• A. False
• B. True
• C. It provides speed only
• D. It provides power data

Answer: (B)

The key idea is that an optical encoder translates mechanical position into electrical signals that reveal where something is in its motion. A light source and a coded disk with slits create a series of pulses as the shaft rotates; counting those pulses tells you the angular position, and the pulse rate indicates speed (and two detectors in quadrature can also show direction). So while you can infer velocity from how fast the pulses come, the primary purpose is to provide position information. It does not provide power data.