A. Parallel
B. Mixed
C. Counter flow
D. Same in either A , B. or C.
Correct Answer: D. Same in either A , B. or C. ✔
Last Updated: March 03, 2019
Related MCQs
- The maximum heat transfer co-efficient from steam heating will be attained when the steam is__________?
- The film co-efficient is decreased due to the presence of non-condensing gases in the vapors. The film co-efficient of superheated vapor as compared to that of saturated vapor is__________?
- Which of the following has maximum thermal conductivity ?
- Thermal diffusivity of a material __________?
- Nusselt number is the ratio of the temperature gradient at the wall to__________?
- What is the unit of thermal conductivity ?
- Tubes are held between top and bottom tube sheets in Calandria type evaporator by keeping__________?
- What is the emissivity of a black body ?
- In SI units, thermal conductivity is expressed in__________?
- In pipe flow, heat is transferred from hot wall to the liquid by__________?
- Heat transfer rate described by Fourier’s law will decrease, if the __________ increases?
- In a co-current double pipe heat exchanger used for condensing saturated steam over the inner tube, if the entrance and exit conditions of the coolant are interchanged, then the rate of condensation will__________?
- Which one gives the monochromatic emissive power for black body radiation ?
- Absorptivity and reflectivity of a perfect black body are respectively __________?
- Water is normally used as a coolant in the heat exchange equipments mainly because of its__________?
- Stefan-Boltzmann law applies to __________ body?
- A BTU/hr.ft.2 °F is equal to__________?
- A __________ evaporator employs an annular downtake?
- With increase in temperature, the thermal conductivity of fresh lubricating oil __________?
- To reduce the tube side pressure drop for the same flow rate, the heat exchanger recommended is __________?
- In case of __________ boiling, the liquid temperature is below the saturation temperature and the boiling takes place in the vicinity of the heated surface?
- For __________ Prandtl number values, the heat conduction will be negligible in the buffer zone?
- Terminal point temperature differences between fluids in case of a heat exchanger is termed as__________?
- A composite wall consists of two plates A and B placed in series normal to the flow of heat. The thermal conductivities are kA and kB and the specific heat capacities are CPA and CPB for plates A and B respectively. Plate B has twice the thickness of plate A. At steady state, the temperature difference across plate A is greater than that across plate B, when__________?
- Overall heat transfer co-efficient of a particular tube is U1. If the same tube with some dirt deposited on either side has coefficient U2, then__________?
- Maximum heat transfer rate is achieved in __________ flow?
- Radiator of an automobile engine is a __________ type of heat exchanger?
- In forced convection, the Nusselt number is a function of __________?
- In a shell and tube type heat exchanger, the floating tube bundle heat arrangement is used__________?
- The Stefan-Boltzmann constant depends on the__________?
- For large heat transfer area requirement, shell and tube heat exchanger is preferred, because it__________?
- A body cools down from 75°C to 70°C in 10 minutes. It will cool down from 70° C to 65° C in __________ minutes?
- Electro-magnetic spectrum range, which is important for radiation varies from __________ microns?
- In a gas-liquid shell and tube heat exchanger, the__________?
- In a shell and tube heat exchanger, square pitch compared to triangular pitch__________?
- Planck’s distribution law is valid for __________ bodies?
- Steam trap is used to__________?
- LMTD for counter-flow and parallel flow heat exchanger will be the same, when the__________?
- Vent pipes are provided in a condenser to __________?
- The advantage of using a 1 – 2 shell and tube heat exchanger over a 1 – 1 shell and tube heat exchanger is__________?
- The equation, Nst = (f/2)/[1 + 5 (Npr – 1) √(f/2)], corresponds to __________ analogy?
- Open pan evaporators are preferred to be used, when the solution to be concentrated is__________?
- When warm and cold liquids are mixed, the heat transfer is mainly by__________?
- At constant temperature, the thermal conductivities of gases __________ with rise in pressure?
- A single pass air heater is connected to a two pass unit. For the air flow rate and other conditions remaining the same, the film heat transfer co-efficient for air will vary in the ratio of__________?
- It is not preferable to use superheated steam in evaporators, because of its very__________?
- __________ heat exchanger is used for chilling oil to be dewaxed?
- If heat transfer rate varies with the time, it is termed as__________?
- The inner wall of a furnace is at a temperature of 700°C. The composite wall is made of two substances, 10 and 20 cm thick with thermal conductivities of 0.05 and 0.1 W.m-1.°C- 1 respectively. The ambient air is at 30°C and the heat transfer co-efficient between the outer surface of wall and air is 20 W.m-2.°C-1. The rate of heat loss from the outer surface in W.m-2is__________?
- The absorptivity of a body is equal to its emissivity __________?
- A perfect black body is a perfect __________ of radiation?