Question

Given below are two statements:
Statement I : Food is cooked in pressure cooker quickly because it retains heat for a longer period.
Statement II : Food is cooked in pressure cooker quickly because boiling point of water increases. In the light of the above statements, choose the correct answer from the options given below

• A. Both Statement I and Statement II are true
• B. Both Statement I and Statement II are false
• C. Statement I is true but Statement II is false
• D. Statement I is false but Statement II is true

Answer 1

The Correct Option is D

To understand why the given statements about pressure cooking are evaluated as such, let's delve into the science of how a pressure cooker works:

Concept Explanation

• A pressure cooker works by trapping steam inside, which increases the pressure inside the cooker. This high pressure allows the temperature inside the cooker to rise above the normal boiling point of water (100°C at standard atmospheric pressure).
• The boiling point of water increases under higher pressure because the molecules need more energy to escape into the gas phase, which requires a higher temperature.

Analysis of Statements

• Statement I: "Food is cooked in pressure cooker quickly because it retains heat for a longer period."
  • This statement is incorrect. While a pressure cooker retains heat, the rapid cooking is primarily due to the increase in boiling point and pressure, not just retention of heat.
• Statement II: "Food is cooked in pressure cooker quickly because boiling point of water increases."
  • This statement is correct. The increased pressure inside the cooker raises the boiling point of water, allowing the food to cook faster due to higher cooking temperatures.

Conclusion

Thus, after evaluating both statements, the correct answer is: "Statement I is false but Statement II is true".