Question

A red hot brick is placed on an iron tripod stand which stands on a large block of copper. The brick loses heat by:
A. Conduction
B. Conduction and radiation
C. Conduction and convection
D. Conduction, convention, and radiation

Answer 1

Hint: conduction happens due to direct contact convention happens when hot molecules move away from the source.

Complete step by step answer:
 Heat is transferred via three main phenomena.
(i) Conduction: conduction transfers heat by direct contact. It happens through direct molecular collision. Kinetic energy of the molecular hot body increases and transfers to the parties with low kinetic energy which are present in the body directly connected to the hot body.
Conduction is the most common form of heat transfer through physical contact.
(ii) conversion: When air or liquid is heated, its molecules travel away from the position of source of heat and any thermal energy with them. This process is called conversion.
(iii) radiation: When a solid or third gains thermal energy, the molecules in it start to bitrate in random direction. This random movement of atoms and molecules in matter causes the ammunition of thermal radiations.
From the above explanation, we can conclude that the brick will lose heat to the iron tripod through conduction.
Which will be transferred to a copper block, which will cause the movement of molecules and as a result, thermal radiation.
Also, the air around the hot brick and thus around the entire system will get hot. Which will move upward and replace itself by cold air. Which will cause the heat loss by conversion.
Therefore, the heat loss will be because of conduction, conversion and radiation.

So, the correct answer is “Option D”.

Note:
It is a simple definition based question. While to think about all the possibilities. Like in this case, we thought about all the possibilities of heat loss.The air around the hot brick and thus around the entire system will get hot.