QQuestion
Define Thermal conductivity. What is the SI unit of Thermal resistance? [2 + 1]
OR
Define volume expansion coefficient of a gas. Find its value from Charles’s law. [1 + 2]
✓Answer
Thermal Conductivity is the ability of a material to conduct heat. It indicates how easily heat passes through a substance.
The SI unit of Thermal Resistance is kelvin per watt (K/W). It measures how much a material resists the flow of heat.
OR
Volume expansion coefficient: The coefficient of volume expansion of a gas at constant pressure is defined as the fraction of its volume at 0°C by which the volume of a fixed mass of gas expands per degree Celsius rise in temperature.
According to Charles’ law, the volume of a given mass of gas at constant pressure expands or contracts by a fixed fraction 1/273 of its volume at 0°C for each degree Celsius rise or fall in temperature.
we get γₚ = 1 \over 273 °C-1
= 0.00366°C-1
Related Questions
More WBBSE Moderate level questions
Define the coefficient of volume expansion of a solid and write its mathematical form. [1 + 2] OR Give one example of each of the thermal expansion of solid, liquid and gaseous substances from everyday experience. [1 + 1 + 1]
Find the length of an iron rod at 110°C if at 10°C, the length of the rod is 20 cm. [Volume expansion coefficient of iron = 36 × 10⁻⁶ /°C]
Define the coefficient of apparent expansion and the coefficient of real expansion of a liquid. Write the relationship between them. [2+1]
Explain the statement: “The coefficient of linear expansion of iron is 12 × 10⁻⁶ /°C”. Give an example of volume expansion of a liquid due to the application of heat. [2+1]
How many types of thermal expansion coefficients are there for a liquid? 0 1 2 3
The coefficient of thermal conduction depends on: (a) The difference in temperature between the two ends of the conductor (b) Property of the material of the conductor (c) The length of the conductor (d) The area of cross-section of the conductor
Why are there gaps at regular intervals between consecutive rails in a railway track? State the relation between linear expansion coefficient (α), superficial expansion coefficient (β) and volume expansion coefficient (γ). [2+1]
Write whether the following statement is true or false : The value of coefficient of linear expansion of solid is the same in celsius scale and in Kelvin scale. OR Arrange diamond, iron and silver in the order of decreasing thermal conductivity.
What is the unit of conductivity? mho. meter -1 ohm. meter -1 mho. meter ohm. meter
Write whether the following statement is True or False: If coefficient of linear expansion of iron is 1.2 × 10⁻⁵ /°C, then coefficient of cubical expansion of iron is 3.6 × 10⁻⁵ /°C.
Write whether the following statement is True or False: Which physical quantity has the unit W m⁻¹ K⁻¹?
The SI unit of thermal conductivity is: (a) W m⁻¹ K⁻¹ (b) cal m⁻¹ °C⁻¹ (c) W m K⁻¹ (d) W m² K⁻¹