A cylinderis made up of twocoaxiallayers,one of radiusR and the outerportions are respectivelymade up of substance of thermalconductivities K and2K . Dterminethe effective thermalconductivitybetween the flatends of the cylinder .

A cylinderis made up of twocoaxiallayers,one of radiusR and the outerp

1.	A cylinderis made up of twocoaxiallayers,one of radiusR and the outerportions are respectivelymade up of substance of thermalconductivities K and2K . Dterminethe effective thermalconductivitybetween the flatends of the cylinder .
Answer» SOLUTION :Here `A_(1) = piR^(2) , K_(1) = K and A_(2) = 4piR^(2) - piR^(2) = 3piR^(2) , K_(2) = 2K` Usingthe expression for the effectivethermal CONDUCTIVITY`K_(eff)` , forslabs in PARALLEL , `K_(eff) = (A_(1)K_(1) + A_(2)K_(2))/(A_(1) + K_(2)) = (piR^(2) (K) + 3piR^(2) (2K))/(piR^(2) + 3piR^(2)) = (7K)/(4)` .