Answer :
Final answer:
The silver wall in a thermo flask prevents heat loss primarily by radiation. It also reduces heat transfer via conduction and convection by its design, but the silver coating is specifically for reflecting radiative heat energy. Therefore, the correct option is C. convection and radiation,
Explanation:
The silver wall in a thermo flask primarily prevents heat loss through radiation. A thermo flask, also known as a vacuum flask, has a silver coating on the walls to reflect radiative heat energy back into the liquid, keeping the content hot or cold.
This reflective surface minimizes the heat transfer that occurs through radiation. However, the design of the flask also addresses other forms of heat transfer; it reduces convection by the use of a vacuum between the double walls, and it reduces conduction by the use of insulating materials.
Heat transfer can occur in three ways: conduction, convection, and radiation. Conduction occurs when there is direct contact between materials, convection involves the movement of fluids (liquids or gases), and radiation can occur without a medium, as it involves the transfer of energy through electromagnetic waves. A silvered wall in a vacuum flask reduces all three to some extent, but it is primarily designed to reflect radiation.
Answer:
The silver wall in a thermos flask prevents heat loss primarily by A. radiation and conduction.
Explanation:
The silvered surface reflects radiant heat, and the vacuum or insulating material between the walls minimizes heat transfer through conduction.
