Heat Transfer Modes Limitations
Understanding how heat moves is key. Conduction and convection are two primary modes of heat transfer. Let's look at their requirements:
- Conduction: Heat transfer through direct contact between particles. It requires a physical medium (solid, liquid, or gas) for particles to collide and transfer energy.
- Convection: Heat transfer through the movement of fluids (liquids or gases). It requires a fluid medium that can circulate, carrying thermal energy with it.
Why Vacuum Prevents Heat Transfer
A vacuum is essentially a space devoid of matter. Since both conduction and convection require a medium:
- In a vacuum, there are no particles to collide (blocking conduction).
- In a vacuum, there is no fluid to move (blocking convection).
Therefore, conduction and convection cannot operate between bodies separated by a vacuum.
Other Options Analysis
The other options represent materials that can act as a medium:
- Aluminium (solid): Allows conduction.
- Ice (solid): Allows conduction. If melting, the resulting water allows conduction and convection.
- Water (liquid): Allows both conduction and convection.
Similar Questions
A black surface absorbs ________ as compared to a white surface, under identical conditions.
- Heat supplied to a system is measured in ______.
- The change of state from ice to water is accompanied by ______.
- _____ is a mode of heat transfer by actual motion of matter.
- _____ is the unit of thermal conductivity.
- A brick wall having a thickness of 24 cm has an inner surface temperature of \(25^{\circ}C\) and an outer surface temperature of \(5^{\circ}C\). The rate of heat loss through per square metre of the wall (thermal conductivity = \(0.15\ J/(s\cdot m \cdot K)\)) is:
Which of the following options is correct when two objects at the same temperature are kept in contact with each other?
Two containers, one painted black and the other painted white, have been kept in sunlight for one hour in the afternoon. Choose the correct observation.
A brass rod (thermal conductivity 109 J/s m K) has an area of cross section 0.04 m 2and length 20 cm. If the two end of the rod are maintained at a temperature difference of 200°C, the rate of heat flow through the rod is ________.
A copper spoon is dipped in hot water. What happens to its other end?
Important Questions from Heat transfer
If a liquid is heated in weightlessness the heat is transmitted through
An iron ball at 60°C is dropped in a mug containing water at 60°C. The heat will
The temperatures of two perfect black bodies A and B are 400 K and 200 K, respectively. If the surface area of A is twice that of B, the ratio of total power emitted by A to that by B is
The volume and temperature of a spherical cavity filled with black body radiation are V and 300 K, respectively. If it expands adiabatically to a volume 2V, its temperature will be closest to
A wooden spoon is dipped in a cup of ice-cream. Its other end
