Heat Transfer - Engineering

Q1:

With increase in temperature, the thermal conductivity of most liquids

A increases

B decreases

C remains same

D first increases upto a certain temperature and then becomes constant

ANS:B - decreases

The thermal conductivity of most liquids actually tends to: b) decreases As the temperature of a liquid increases, the average distance between molecules also increases due to thermal expansion. This increase in intermolecular distance leads to a reduction in the frequency and efficiency of molecular collisions, which are responsible for thermal energy transfer. Consequently, the thermal conductivity of the liquid decreases with increasing temperature. This phenomenon is particularly noticeable in liquids that exhibit significant changes in viscosity or molecular structure with temperature, which can further affect their thermal conductivity. Therefore, as the temperature of most liquids increases, their thermal conductivity typically decreases.