Exam Question

### (a) Definition of Proportional Control Action
Proportional control is a type of linear feedback control where the corrective action or output from the controller is directly proportional to the error signal. The error is the difference between the desired Set Point (SP) and the measured Process Variable (PV).
**Key Concepts:**
1. **Direct Proportionality:** A larger deviation from the setpoint results in a correspondingly larger corrective output. Conversely, a small error produces a small corrective output. This provides a modulating, rather than a simple ON/OFF, response.