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 copper spoon is dipped in hot water. What happens to its other end?
- Generally, what is the process of heat transfer in liquids?
- Which of the following processes is primarily responsible for heat loss from a hot utensil?
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 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:
Important Questions from Heat transfer
The process by which heat is transferred from the hotter end to the colder end of an object is known as ______.
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
