Heat transfer by natural convection is enhanced in system with__________________?
Correct answer: B. High co-efficient of thermal expansion
- A. High viscosity
- B. High co-efficient of thermal expansion
- C. Low temperature gradients
- D. Low density change with temperature
Explanation
Natural convection is strengthened by a large coefficient of thermal expansion because a given temperature difference produces a larger density change and therefore stronger buoyancy. High viscosity has the opposite effect by resisting motion.
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