A cube at high temperature is immersed in a constant temperature bath. It loses heat from its top, bottom and side surfaces with heat transfer coefficients of h₁, h₂ and h₃ respectively. The average heat transfer coefficient for the cube is

A. $${{\text{h}}_1} + {{\text{h}}_2} + {{\text{h}}_3}$$

B. $${\left( {{{\text{h}}_1}{{\text{h}}_2}{{\text{h}}_3}} \right)^{\frac{1}{3}}}$$

C. $$\frac{1}{{{{\text{h}}_1}}} + \frac{1}{{{{\text{h}}_2}}} + \frac{1}{{{{\text{h}}_3}}}$$

D. None of these

Answer: Option C

Solution(By Examveda Team)

A cube at high temperature is immersed in a constant temperature bath. It loses heat from its top, bottom and side surfaces with heat transfer coefficients of h₁, h₂ and h₃ respectively. The average heat transfer coefficient for the cube is $$\frac{1}{{{{\text{h}}_1}}} + \frac{1}{{{{\text{h}}_2}}} + \frac{1}{{{{\text{h}}_3}}}.$$