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GATE 2020 ME (ME2) – Question 27

Thermal Engineering Applications · I.C. Engines: Otto, Diesel and dual cycles · 1 mark · Multiple choice

For an air-standard Diesel cycle, ______.

  1. heat addition is at constant volume and rejection at constant pressure
  2. heat addition and rejection are both at constant pressure
  3. heat addition is at constant pressure and rejection at constant volume
  4. heat addition and rejection are both at constant volume

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Correct answer: (C) heat addition is at constant pressure and rejection at constant volume

Explanation

The ideal Diesel cycle adds heat at constant pressure after isentropic compression. After isentropic expansion it rejects heat at constant volume. Thus **C**. Constant-volume heat addition characterizes the Otto cycle.