Question

when air and fuel are burned in an engine, the process is called combustion. what type of combustion process is used in modern automobiles?

a. internal combustion

b. reserve combustion

c. external combustion

d. spontaneous combustion

Explanation:

Modern automobiles use internal combustion engines where the combustion of fuel (with air) occurs inside the engine cylinders (internal to the engine), converting chemical energy to mechanical energy. Reserve combustion is not a standard combustion type for engines. External combustion (e.g., steam engines) has combustion outside the engine working fluid. Spontaneous combustion is uncontrolled ignition without an external spark/heat source, not used in automobile engines. So the correct type is internal combustion.

Answer:

a. Internal combustion