Read the following statements carefully:
Statement I: A pressure cooker operates by decreasing the pressure inside, which lowers the boiling point of water.
Statement II: Food cooks faster in a pressure cooker because the higher pressure allows water to boil at a temperature above 100°C.
Statement III: The superheated steam within the cooker increases the rate of heat transfer to the food, leading to faster cooking.
Which of the statements given above is/are correct?
Show answer & explanation
Correct answer: A
Explanation
Correct Answer: Only II and III are correct
Explanation: This question is based on the working principle of a pressure cooker, related to basic physics and thermodynamics in Physics.
Statement I → Incorrect
It says pressure cooker works by decreasing pressure
Wrong: A pressure cooker actually works by increasing pressure, not decreasing it
Increased pressure raises the boiling point of water
Statement II → Correct
Higher pressure → water boils above 100°C
This allows food to cook faster
Statement III → Correct
High-pressure steam becomes superheated steam
It transfers heat more efficiently → faster cooking
Additional Key Facts
Normal boiling point of water = 100°C at 1 atm pressure
In a pressure cooker: Pressure increases and Boiling point increases (~120°C or more)
Used widely for faster cooking and energy efficiency
Potential Exam Questions (with Answers)
Q. What is wrong in Statement I of the question?
Ans: It incorrectly states that pressure decreases inside the cooker
Q. Which state of matter transfers heat efficiently inside a pressure cooker?
Ans: Superheated steam