Answer:
Q=112.31 W/m
Step-by-step explanation:
Given that
Oil temperature T₁= 150°C
Air temperature T₂= 20°C
Heat transfer coefficient h= 11 W/m²K
Diameter ,d= 25 mm
The heat loss given as
Q= h A ΔT
A= πdL
Q= h ( πdL)ΔT
Heat loss per unit length
Q= h ( πd)ΔT
Now by putting the values

Q=112.31 W/m
Therefore heat loos will be 112.31 W/m