MCQs
Total Questions : 448
| Page 33 of 45 pages
Question 321. A designer chooses the values of fluid flow rates and specific heats in such a manner that the heat capacities of the two fluids are equal. A hot fluid enters the counter flow heat exchanger at 100°C and leaves at 60°C. A cold fluid enters the heat exchanger at 40°C. The mean temperature difference between the two fluids is
Answer: Option C. -> 20°C
Answer: Option A. -> All of these
Answer: Option C. -> Convection
Answer: Option B. -> Both (A) and (B)
Answer: Option B. -> When system is under thermal equilibrium
Answer: Option B. -> All of these
Answer: Option A. -> One dimensional cases only
Answer: Option D. -> The better insulation must be put inside
Answer: Option A. -> Added insulation will increase heat loss
Question 330. Fourier's law of heat conduction is (where Q = Amount of heat flow through the body in unit time, A = Surface area of heat flow, taken at right angles to the direction of heat flow, dT = Temperature difference on the two faces of the body, dx = Thickness of the body, through which the heat flows, taken along the direction of heat flow, and k = Thermal conductivity of the body)
Answer: Option D. -> k. A. (dT/dx)