Measurement of heat conductivity a metal panel of area a = 100 cm² and thickness y = 0.5 cm was found to conduct heat at a rate of 3 w at steady state with temperatures to = 25 °c and t, = 30 °c imposed on the two main surfaces. what is the average thermal conductivity of the material at this temperature range?

The average thermal conductivity of the material at this temperature range is 3*10^(-9) W/mK.

Explanation:

The heat flow through this area of the metal panel can be expressed as:

being A the surface area, k the thermal conductivity, T2 and T1 the temperatures in each side and Y the thickness of the metal panel.

We have to rearrange the equation to clear k:

The average thermal conductivity of the material at this temperature range is 3*10^(-9) W/mK.

hydrocarbons are organic compounds that contain only hydrogens and carbons. they can be saturated (those which contain only carbon-carbon single bonds) or unsaturated (those which contain carbon-carbon double or triple bonds) in nature. hydrocarbons can undergo several reactions like substitution, elimination etc.  

on substituting one or more hydrogen atoms in hydrocarbon it results in the formation of haloalkane. as the halogen atoms are large compared to the carbon and hydrogen atoms, due to which the molecular weight increases and the bond become polar because of presence electronegative halogen atom and results in the increase in boiling point of the haloalkane.

thus, the correct option is (b) that is the boiling point of the new compound increases on substituting a hydrogen atom with a halogen in a hydrocarbon.