Question

which type of engine uses a power piston and a displacer piston? select one: a. steam engine b. deutz engine c. stirling engine d. wankel engine

Explanation:

A Stirling engine is a heat - engine that operates by cyclic compression and expansion of air or other gas (the working fluid) at different temperatures, resulting in a net conversion of heat energy to mechanical work. It uses a power piston and a displacer piston. The displacer piston moves the working gas between the hot and cold ends of the cylinder, while the power piston extracts work from the expanding and contracting gas.
A steam engine typically has a piston that is directly driven by steam pressure. A Deutz engine is a type of internal combustion engine (diesel engine in some cases) which has pistons but not in the Stirling - engine's power - displacer piston configuration. A Wankel engine is a rotary engine and does not use pistons in the traditional reciprocating sense like a piston - based engine with power and displacer pistons.

Answer:

C. Stirling engine