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19/01/22, 15:22 IC Engines - January 19, 2022. Part A (10 points) https://forms.office.com/Pages/ResponsePage.aspx?id=K3EXCvNtXUKAjjCd8ope64cHfHFJHqdBkPyq7vedZGJUODFZNUlBTTgzTkYxUUpGRV… 1/3 IC Engines - January 19, 2022. Part A (10 points) If the intake valve diameter is reduced, we expect that the volumetric efficiency:1. A) will decrease mainly at high speeds B) will decrease mainly at low speeds C) will decrease in a similar way at all engine speeds D) will decrease mainly at low loads. The two-stroke engine is:2. A) always more efficient than the four-stroke engine B) always less efficient than the four-stroke engine C) characterized by higher thermal and mechanical stresses than the four-stroke D) applied only in the case of very small displacement and effective power. Pulse turbocharging:3. A) does not determine fluctuations of the turbine efficiency B) requires a double-entry compressor C) damps the pressure perturbations in a large volume exhaust manifold D) reduces the “turbo-lag” issue. The waste-gate valve in a turbocharged SI engine must be opened:4. A) to allow the operation of high pressure EGR B) at high engine speeds, to control the turbine power C) at low engine speeds, to control the turbine power D) to increase the compressor boost pressure. 19/01/22, 15:22 IC Engines - January 19, 2022. Part A (10 points) https://forms.office.com/Pages/ResponsePage.aspx?id=K3EXCvNtXUKAjjCd8ope64cHfHFJHqdBkPyq7vedZGJUODFZNUlBTTgzTkYxUUpGRV… 2/3 In a spark ignition engine, when the burnt gas has reached 50% of the chamber volume, the burnt mass fraction: 5. A) is equal to 20% B) is equal to 50% C) is equal to 75% D) is equal to 100% Knock is a form of abnormal combustion which, if not controlled, may occur:6. A) during the expansion stroke of the cycle B) mainly in…