Q4 M7 - HEAT, WORK AND ENERGY

Which of the following device converts thermal energy into mechanical work?

• heat engine
• rice cooker
• refrigerator
• air conditioner

What is the effect of the accumulation of heat from diesel, gasoline, and industrial engines?

• Thermal energy
• Thermal pollution
• Thermal expansion
• Thermal radiation

Which of the following is described as the ratio of the useful work done to the heat provided on how well a machine operates?

• Thermal efficiency
• Thermal expansion
• Thermal energy
• Thermal pollution

Which of the following is a CORRECT sequence of a four-cycle stroke of a gasoline engine?

• Compression Power Intake Exhaust
• Intake Compression Power Exhaust
• Exhaust Compression Power Intake
• Power Intake Exhaust Compression

What is the efficiency of a gasoline engine that receives 192.75J of energy from combustion and loses 125.25J by heat to exhaust during one cycle?

• 0.35
• 0.36
• 0.37
• 0.38

Suppose a steam engine receives steam at 600K. The engine uses part of this thermal energy for work. It exhausts the rest to a condenser at a temperature of 350K. What is the maximum efficiency of this steam engine?

• 0.4165
• 0.4166
• 0.4167
• 0.4168

What is the thermal efficiency of a steam engine if the temperature is 30°C and 88°C in the cold and hot reservoir, respectively?

• 0.1265
• 0.1406
• 0.1567
• 0.1607