Steam Boilers, Engines, Nozzles and Turbines
Coke is produced by

Strongly heating coal continuously for about 48 hours in the absence of air in a closed vessel
Enriching carbon in the coal
Heating wood in a limited supply of air at temperatures below 300°C
Pulverizing coal in inert atmosphere

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Steam Boilers, Engines, Nozzles and Turbines
The function of a piston in a steam engine is

To guide motion of the piston rod and to prevent it from bending
To transfer motion from the piston to the cross-head
None of these
To convert heat energy of the steam into mechanical work id) to exhaust steam from the cylinder at proper moment

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