railway RRB JE (CBT I + CBT II) Mock Test 2024 Heat Transfer Conduction Critical Thickness of Insulation
The critical radius of insulation for a cylindrical object, like a pipe, is the radius at which:
1
the heat transfer rate is minimized.
2
the inner surface temperature is minimized.
3
the heat transfer rate is maximized.
4
the outer surface temperature is maximized.