Pressure cooker, thermos flask (applications)

Correct Answer

📖 Governing Law / Core Concept

The boiling point of a liquid increases with pressure, as described by the Clausius-Clapeyron relation.

🧪 Step-by-Step Breakdown

Inside a pressure cooker, the pressure is increased above atmospheric levels. The relationship between pressure and boiling point is expressed by:

Where:

• T: Boiling point [°C]
• L: Latent heat of vaporization [J/kg]
• R: Specific gas constant [J/(kg·K)]
• P_1: Initial pressure [Pa]
• P_2: Final pressure [Pa]
• T_1: Initial boiling point [°C]

As the pressure (P) increases, the boiling point (T) also increases, which allows food to cook faster due to a higher temperature.

🔍 Option Analysis

• Option (B): Incorrect. Decreasing the boiling point would slow down cooking.
• Option (C): Incorrect. The melting point is not relevant in cooking under pressure.
• Option (D): Incorrect. Decreasing melting point does not apply to boiling water.

⚡ Mnemonic / Speed-Run

Remember: "Pressure Up, Cook Hotter!" which helps recall that increased pressure in a cooker raises the boiling point.

6. Visual Suggestion

📖 Factual Verification & Reference