railway RRB JE (CBT I + CBT II) Mock Test 2024 Heat Transfer Conduction Critical Thickness of Insulation
A hollow pipe of 1 cm outer diameter is to be insulated by thick cylindrical insulation having thermal conductivity 1 W/mK. The surface heat transfer coefficient on the insulation surface is 5 W/m2K. What is the minimum effective thickness of insulation for causing the reduction in heat leakage from the insulated pipe?
1
19 cm
2
15 cm
3
19.5 cm
4
20 cm