DIESEL LOCO - HEAT ENGINE
Heat engine - Heat engine is the machine which converts heat energy into mechanical energy.
Heat engine are of two types.
a. External combustion engine - In External combustion engine fuel is burnt or ignited outside the engine cylinder. So it is called as external combustion engine e.g. Steam engine.
b. Internal combustion engine - In internal combustion engine fuel is burnt or ignited inside the engine cylinder so it is called internal combustion engine e.g. Petrol engine, diesel engine.

