Otto Cycle Efficiency and Processes

The video tutorial introduces the Otto cycle, a theoretical model used to understand spark ignition internal combustion engines. It covers the PV diagram, detailing processes like adiabatic compression and constant volume heat addition. The derivation of the Otto cycle's efficiency is explained, highlighting the importance of compression and expansion ratios. The final efficiency equation is presented, showing its dependence on the compression ratio and adiabatic index. The video concludes with a summary of how increasing the compression ratio enhances efficiency.

What type of engines use the Otto cycle?

• Steam engines

• Petrol engines

• Electric engines

• Diesel engines

In the Otto cycle, what happens during the adiabatic compression process?

• Pressure and volume decrease, temperature increases

• Pressure and temperature decrease, volume increases

• Pressure decreases, temperature and volume increase

• Pressure and temperature increase, volume decreases

During which process in the Otto cycle is heat added at constant volume?

• Constant volume heat rejection

• Constant volume heat addition

• Adiabatic expansion

• Adiabatic compression

Which process in the Otto cycle involves heat rejection at constant volume?

• Adiabatic expansion

• Constant volume heat addition

• Constant volume heat rejection

• Adiabatic compression

What is the formula for the efficiency of the Otto cycle?

• 1 - (T4 - T1) / (T3 - T2)

• 1 - (V4 - V1) / (V3 - V2)

• 1 - (T3 - T2) / (T4 - T1)

• 1 - (P4 - P1) / (P3 - P2)

What is the compression ratio in the Otto cycle?

• T2 / T1

• V1 / V2

• V2 / V1

• P2 / P1

How is the expansion ratio defined in the Otto cycle?

• V4 / V3

• V3 / V4

• T3 / T4

• P3 / P4

What is the relationship between compression ratio and efficiency in the Otto cycle?

• Efficiency is inversely proportional to compression ratio

• Efficiency increases with increasing compression ratio

• Efficiency is independent of compression ratio

• Efficiency decreases with increasing compression ratio

What is the final equation for the efficiency of the Otto cycle in terms of compression ratio?

• 1 - 1 / (r^gamma)

• 1 - 1 / (r^(gamma-1))

• 1 - r^gamma

• 1 - r^(gamma-1)

What is the significance of the adiabatic index in the Otto cycle?

• It is irrelevant to the cycle

• It defines the volume ratio

• It affects the efficiency calculation

• It determines the pressure ratio