Consider two long, poles of same diameter and uniform cross sectional area throughout its length but different materials. the ends of each rod is attached to the base whose surface is maintained at 120°c, the surfaces of the rods are exposed to wind at 10°c. the temperatures of the rods at different points along its length were measured and it was found that at the positions xa=0.15 m and xb= 0.075 m, where x is measured from the base surface, the temperatures were same. find the value of ka for rod b, if the thermal conductivity of rod a is known to be ka= 60 w/mk