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

h1 + h2 + h3
(h1h2h3)1/3
none of these
✅ The correct answer is option D.

In a boot-strap air evaporative cooling system, the evaporator is provided

between the combustion chamber and the first heat exchanger
between the first heat exchanger and the secondary compressor
between the secondary compressor and the second heat exchanger
between the second hea
✅ The correct answer is option D.