Answer:
The thermal conductivity of A is given by the formula 
Explanation:
Thermal conductivity is the ability of a material to transfer a quantity of heat.
Since thermal conductivity is given by the letter H, let's say the thermal conductivity of A is Ha, and for B, Hb. Ha is half that of Hb, that is
.
Thermal conductivity is given by the formula 
Where k is a constant called the thermal conductivity, which depends on the material; A is the cross sectional area of the rod; T2 is final temperature and T1 is initial temperature; L is length of the rod.
Then we can calculate Hb using 
Ab is cross sectional for rod of material B, T2b and T1b are temperatures in material B and Lb is length of material B, which is 0.5.
Finally, we can write Ha in terms of Hb. Since 2 multiplied by 0.5 is 1 we get:
