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 lid
- 2.Temperature of the flame
- 3.Weight of the lid
Select the correct answer using the code given below.
Answer & explanation
Answer: (c) 1 and 3 only
The cooking temperature is the boiling point of water at the pressure held inside the cooker, and that pressure is fixed by the weight of the lid's regulator and the area of the vent hole it covers. A hotter flame only makes steam faster; it does not raise the cooking temperature.
- ✓ 1. Steam escapes through the vent hole once its push (pressure × hole area) exceeds the regulator's weight. So the hole area helps decide how much pressure builds up, and water boils at a higher temperature at higher pressure.
- ✗ 2. A bigger flame makes steam sooner, but once the regulator lifts, the extra steam simply escapes. The pressure, and hence the boiling temperature, stays the same.
- ✓ 3. The weight placed over the vent is what the steam must lift. A heavier weight lets more pressure build up, so the water boils at a higher temperature (well above 100 °C).
Remember · Water boils at a higher temperature under higher pressure. In a pressure cooker the vent weight and vent-hole area set the pressure; the flame only sets how fast it is reached.
Sources
- NASA, Is There Water on Mars? An Educator's Guide, Activity 3 (pressure cooker and boiling point) ↗ “The high pressure inside the cooker requires that water reaches a higher temperature in order to boil. This higher temperature cooks the food faster. … Make sure students understand that pressure cookers are used to increase the pressure inside the pot.”
- US Patent Office, US Patent 4,238,996, Two-staged pressure cooker (description of the weight over the steam outlet) ↗ · reference work “the weight 9 has a cup shape covering the steam passage 8, and is of a weight which allows the weight 9 to be pushed up by a steam pressure inside the chamber 4”
Question and answer: UPSC's official GS Paper I (2021, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 1 Oct 2026 (how we verify). ·