Thermal Properties of Matter - Online Test
Q1. If V is the initial volume, ΔV the fractional change in volume of a substance for temperature change ΔT, the coefficient of volume expansion, αV is defined as
Answer : Option A
Explaination / Solution:
increase in volume per unit original volume per Kelvin rise in temperature is called coefficient of volume expansion,
Q2. Which of these materials has low coefficient of volume expansion αV ?
Answer : Option A
Explaination / Solution:
Glass is a ceramic material made from silica.So that it has lower coefficient of volume expansion in comparison to metal and liquid.
Q3. Which of these materials have high coefficients of volume expansion ?
Answer : Option C
Explaination / Solution:
Alcohal has higher coefficient of volume expansion in comparison to glass and Invar.
Q4. expansion of water is called anomalous because
Answer : Option B
Explaination / Solution:
Liquids expand on heating and contract on cooling at moderate temperatures. But water exhibits an exceptional behaviour. When it is heated from 0 ºC, it actually contracts rather than expanding, up to 4 ºC. The volume of water is minimum at 4 ºC. Beyond 4 ºC, water starts expanding.This behaviour of water between 0 ºC and 4 ºC is called anomalous expansion of water..
Q5. Animal and plant life in lakes and ponds are not destroyed because
Answer : Option D
Explaination / Solution:
As and when water is cooled down to its freezing point the thickness T of the ice layer increases. The increase in thickness of ice decreases the rate of cooling of water and thus freezing process slows down.
Q6. For an ideal gas the coefficient of volume expansion at constant pressure is
Answer : Option B
Explaination / Solution:
γ=ΔVVΔTPV=nRTV=nRTPPΔV=nRΔTΔV=nRΔTPγ=nRΔTPnRTP×1ΔT=nRΔTP×PnRT×1ΔT=1T
Q7. Thermal stress is stress induced in solids
Answer : Option D
Explaination / Solution:
If temperature deformation is permitted to occur freely, no load or stress will beinduced in the structure. In some cases where temperature deformation is not permitted, an internal stress is created. The internal stress created is termed as thermal stress .
Q8. If m is the mass of a substance, ΔQ the energy required to raise the temperature by ΔT the specific heat is given by
Answer : Option D
Explaination / Solution:
The specific heat is the amount of heat per unit mass required to raise the temperature by one degree Celsius.
Q9. The latent heat of fusion is.
Answer : Option C
Explaination / Solution:
The enthalpy of fusion of a substance, also known as (latent) heat of fusion, is the change in its enthalpy resulting from providing energy, typically heat, to a specific quantity of the substance to change its state from a solid to a liquid at constant pressure.
Q10. The latent heat of vaporization is.
Answer : Option B
Explaination / Solution:
Latent heat of vaporization is actually the total amount of enthalpy (a kind of energy/heat) necessary to accomplish a phase change for a liquid or gas at the boiling/condensation point. Phase changes are generally considered at constant pressure, rather than constant volume.
