Question

Ice cube kept in a well-insulated thermos flask, is an example of which system?

• A. Closed system
• B. Open system
• C. Isolated system
• D. Heterogeneous system

Hint:

Think of the word "Isolated" as being "lonely." The ice in the thermos is completely cut off from the rest of the world—no heat gets in, and no water gets out.

Answer 1

The Correct Option is C

1. Types of Thermodynamic Systems:

• Open System: Both mass and energy can cross the boundary (e.g., a turbine or an open cup of coffee).

• Closed System: Only energy can cross the boundary; mass remains constant (e.g., a sealed piston-cylinder).

• Isolated System: Neither mass nor energy can cross the system boundary.

2. Analyzing the Thermos Flask: A "well-insulated thermos flask" is designed specifically to prevent any interaction with the external environment.

• Mass Transfer: Since the flask is sealed, no ice or water vapor can escape or enter.

• Energy Transfer: The vacuum insulation and silvered walls are designed to minimize heat transfer by conduction, convection, and radiation.