"A transducer is more general than a sensor." Comment. 

Question :

"A transducer is more general than a sensor." Comment. 

A sensor is a device which can quantitatively measure a certain physical quantity. A transducer is a device which converts one physical quantity to another from of physical quantity, e.g., acceleration to voltage or voltage to pressure. Therefore, a transducer can be a sensor when it is used to measure a certain physical quantity. But the transducer can also be an actuator when the (electrical) input is converted to, for example, force. So a transducer is more general than a sensor.