Q68 · UPSC Prelims 2021 · Set A · Science and Technology

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In a pressure cooker, the temperature at which the food is cooked depends mainly upon which of the following?1.Area of the hole in the lid2.Temperature of the flame3.Weight of the lidSelect the correct answer using the code given below

A 1 and 2 only
B 2 and 3 only
C 1 and 3 only
D 1, 2 and 3

Correct answer: (c) 1 and 3 only

Explanation

  1. A

    1 and 2 only

    1 and 2 only. Flame temperature does not set the boiling point once the cooker is at its rated pressure.

  2. B

    2 and 3 only

    2 and 3 only. The vent area matters; the flame does not, as keyed.

  3. C

    1 and 3 only

    1 and 3 only. Hole in the lid and weight of the whistle set the pressure, hence the cooking temperature.

  4. D

    1, 2 and 3

    All three. Statement 2 is the miss.

Summary. Official key is (c) 1 and 3 only. Cooking temperature in a pressure cooker is the boiling point of water at the pressure fixed by the vent and the weight. Turning the flame up mainly shortens the time to that pressure, not the temperature once it is reached.