A thin walled metal tank of surface area 5m² is filled with water and contains an immersion heater dissipating 1 kW. The tank is covered with 4 cm thick layer of insulation whose thermal conductivity is 0.2 W/m-K. The outer face of the insulation is 25oC. Find the temperature of the tank in the steady state
Physics · Thermodynamics
JEE Mains

Question

A thin walled metal tank of surface area 5m² is filled with water and contains an immersion heater dissipating 1 kW. The tank is covered with 4 cm thick layer of insulation whose thermal conductivity is 0.2 W/m-K. The outer face of the insulation is 25oC. Find the temperature of the tank in the steady state

Physics · Thermodynamics

G1 Physics · Accepted Answer

In steady conduction, heat current is H=kAΔT/L. Treat each segment as a thermal resistance Rₜₕ=L/(kA); series resistances add and parallel heat currents add. Substituting the given values gives 65.