The equivalent diameter for the annulus of a double pipe heat
exchanger, whose inner pipe has fins on the outside is __________ compared
to the same size pipes without fins.
(A) More
(B) Less
(C) Same
(D) Unpredictable
Description : A fluid is flowing inside the inner tube of a double pipe heat exchanger with diameter 'd'. For a fixed mass flow rate, the tube side heat transfer coefficient for turbulent flow conditions is proportional to (A) d 0.8 (B) d -0.2 (C) d -1 (D) d -1.8
Last Answer : (B) d -0.2
Description : A concentric double pipe heat exchanger as compared to the shell and tube heat exchanger for the same heat load requires (A) Less heating surface (B) More space (C) Lower maintenance cost (D) None of these
Last Answer : (B) More space
Description : 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 ... Decrease (C) Remain unchanged (D) Either increase or decrease; depends on the coolant flow rate
Last Answer : (C) Remain unchanged
Description : __________ heat exchanger is used for chilling oil to be dewaxed. (A) U-tube (B) Double pipe (C) Fixed tube
Last Answer : (B) Double pipe
Description : A compound pipe is required to be replaced by a new pipe. The two pipes are said to be equivalent, if (A) Length of both the pipes is same (B) Diameter of both the pipes is same (C) Loss of ... discharge of both the pipes is same (D) Loss of head and velocity of flow in both the pipes is same
Last Answer : Answer: Option C
Description : Pick out the wrong statement. (A) Superheated steam is preferably not used for process heating because of its low heat transfer film co-efficient (B) In a shell and tube heat exchanger ... surface heat exchangers, when the direction of fluid flow is parallel to the axis of the tube
Last Answer : (C) S.I. unit of fouling factor is Watt/m2 .°K
Description : Nominal Pipe Size (NPS) of a pipe less than 12 inches in diameter indicates its (A) Inner diameter (B) Outer diameter (C) Thickness (D) Neither inner nor outer diameter
Last Answer : (D) Neither inner nor outer diameter
Description : Nominal size of a pipe is an indication of its __________ diameter. (A) Inner (B) Outer (C) Approximate (D) None of these
Last Answer : (C) Approximate
Description : The pressure outside a bubble/droplet of liquid is __________ the internal pressure. (A) Greater than (B) Less than (C) Equal to (D) Unpredictable; depends on the bubble size
Last Answer : Option B
Description : A dephlegmator is a (A) Total condenser (B) Vacuum evaporator (C) Partial condenser (D) Double pipe heat exchanger
Last Answer : (C) Partial condenser
Description : Which type of heat exchanger is preferred for heavy heat loads? (A) Double pipe (B) Plate fine (C) Series and parallel set of shell and tube (D) None of these
Last Answer : (C) Series and parallel set of shell and tube
Description : Air is best heated with steam in a heat exchanger of (A) Plate type (B) Double pipe type with fin on steam side (C) Double pipe type with fin on air side (D) Shell and tube type
Last Answer : (C) Double pipe type with fin on air side
Description : In reactions involving solids and liquids (where change in volume is negligible), the heat of reaction at constant pressure as compared to that at constant volume is (A) More (B) Less (C) Same (D) Unpredictable; depends on the particular reaction
Last Answer : (C) Same
Description : In a shell and tube heat exchanger, square pitch compared to triangular pitch (A) Gives a higher shell side pressure drop (B) Gives a lower shell side pressure drop (C) Can pack more surface area into a shell of given diameter (D) None of these
Last Answer : (A) Gives a higher shell side pressure drop
Description : All pipes of a particular nominal size have the same (A) Inside diameter (B) Outside diameter (C) Thickness (D) None of these
Last Answer : (B) Outside diameter
Description : For a fluid flowing in an annulus space, the wetted perimeter for heat transfer and pressure drop are (A) Same (B) Different (C) Never different (D) Linearly related
Last Answer : (B) Different
Description : Pick out the wrong statement. (A) The condensing film co-efficient is about 3 times lower for vertical condenser as compared to the equivalent horizontal condenser for identical situation ( ... in a heat exchanger is controlled by the value of the film co-efficient, which is higher
Last Answer : (D) Overall heat transfer co-efficient in a heat exchanger is controlled by the value of the film co-efficient, which is higher
Description : In a heat exchanger with steam outside the tubes, a liquid gets heated to 45°C, when its flow velocity in the tubes is 2 m/s. If the flow velocity is reduced to 1 m/s, other things remaining ... than 45°C (B) More than 45°C (C) Equal to 45°C (D) Initially decreases and remains constant thereafter
Last Answer : (B) More than 45°C
Description : Consider two pipes of same length and diameter through which water is passed at the same velocity. The friction factor for rough pipe is f1 and that for smooth pipe is f2 . Pick out the correct statement. (A) f1 = f2 (B) f1 < f2 (C) f1 > f2 (D) Data not sufficient to relate f1 & f2
Last Answer : (C) f1 > f2
Description : Weight of 1 m3 of humid air as compared to 1 m3 of dry air, under the same conditions, is (A) Less (B) More (C) Same (D) Unpredictable
Last Answer : (A) Less
Description : In a stabilised soap bubble, pressure inside it compared to external pressure is (A) More (B) Less (C) Same (D) Unpredictable
Last Answer : (A) More
Description : A compound pipe of diameter d1, d2 and d3 having lengths l1, l2 and l3 is to be replaced by an equivalent pipe of uniform diameter d and of the same length (l) as that of the compound pipe. The size of the equivalent pipe is given by (A) l/d² = + + (B) l/d³ = + ) + (C) = + + (D)
Last Answer : Answer: Option D
Description : The specific fuel consumption of a petrol engine compared to diesel engine of same H.P is A. same B.more C. less D. unpredictable
Last Answer : ANSWER : B
Description : The air requirement of a petrol engine during starting compared to the theoretical air requirement for complete combustion is A. more B.unpredictable C. same D. less
Last Answer : ANSWER : D
Description : The area of actual indicator diagram on an air compressor as compared to area of ideal indicator diagram is A. Less B. More C. Same D. Unpredictable
Description : An ideal gas as compared to a real gas at very high pressure occupies (a) more volume (b) less volume (c) same volume (d) unpredictable behaviour (e) no such correlation.
Last Answer : Answer : a
Description : . If all the conditions and dimensions are same, then the ratio of velocity through the tubes of a double pass heat exchanger to that through the single pass heat exchanger is (A) 1 (B) 2 (C) 1/2 (D) 4
Last Answer : (B) 2
Description : In case of end to end connection of two or more pipes in series, the __________ each pipe. (A) Same rate of flow passes through (B) Head loss is same through (C) Rate of flow in each pipe is proportional to the length of (D) Total flow rate is the sum of flow rate in
Last Answer : (A) Same rate of flow passes through
Description : Steam is to be condensed in a shell and tube heat exchanger, 5 m long with a shell diameter of 1 m. Cooling water is to be used for removing the heat. Heat transfer co-efficient ... ) Horizontal heat exchanger with steam on tube side (D) Horizontal heat exchanger with steam on shell side
Last Answer : (B) Vertical heat exchanger with steam on shell side
Description : Pipes having diameter 14 inches or more are designated by their (A) Outside diameter (B) Inside diameter (C) Schedule number (D) None of these
Last Answer : (A) Outside diamete
Description : The loss of head due to viscosity for laminar flow in pipes is (where d = Diameter of pipe, l = Length of pipe, v w = Specific weight of the flowing liquid) (A) 4 (B) 8 (C) 16 (D) 32
Description : Even though heat transfer co-efficient in boiling liquids is large, use of fins is advantageous, when the entire surface is exposed to __________ boiling. (A) Film (B) Nucleate (C) Transition (D) All modes of
Last Answer : Option A
Description : Which of the following two quantities when same, makes one pipe system equivalent to another pipe system? (A) Head & discharge (B) Length & discharge (C) Length & diameter (D) Friction factor & diameter
Last Answer : (A) Head & discharge
Description : In case of parallel flow heat exchanger, the lowest temperature theoretically attainable by the hot fluid is __________ the outlet temperature of the cold fluid. (A) Equal to (B) More than (C) Less than (D) Either more or less than (depending upon the fluid)
Last Answer : (A) Equal to
Description : The change in evaporator temperature in a refrigeration cycle, as compared to change in condenser temperature, influences the value of C.O.P. (a) more (b) less (c) equally. (d) unpredictable
Last Answer : Ans: a
Description : A 2-4 heat exchanger involves (A) Only counter-flow of fluids (B) Only parallel-flow of fluids (C) Both counter and parallel-flow of the fluids (D) Smaller pressure drop compared to 1-2 exchanger
Last Answer : (C) Both counter and parallel-flow of the fluids
Description : In a shell and tube heat exchanger, the height of 25 percent cut baffles is equal to (where, D = inside diameter of shell). (A) 0.25 D (B) 0.50 D (C) 0.75 D
Last Answer : (C) 0.75 D
Description : Shell side pressure drop in a shell and tube heat exchanger does not depend upon the (A) Baffle spacing & shell diameter (B) Tube diameter & pitch (C) Viscosity, density & mass velocity of shell side fluid (D) None of these
Last Answer : (D) None of these
Description : In case of a shell and tube heat exchanger, the minimum and maximum baffle spacing is respectively (where, D = inside diameter of the shell) (A) D/5 and D (B) D/2 and 2 D (C) D/4 and 2 D (D) D and 2 D
Last Answer : (A) D/5 and D
Description : In a shell and tube heat exchanger, the shell side fluid velocity can’t be changed by changing the (A) Tube layout (B) Tube diameter (C) Tube pitch (D) Number of baffles
Last Answer : (B) Tube diameter
Description : Minimum recommended baffle spacing in a shell and tube heat exchanger is about (where, D = shell diameter). (A) 0.2 D (B) 0.5 D (C) 0.66 D (D) 0.80 D
Last Answer : (A) 0.2 D
Description : In an extended surface heat exchanger, fluid having lower co-efficient (A) Flows through the tube (B) Flows outside the tubes (C) Can flow either inside or outside the tubes (D) Should not be used as it gives very high pressure drop
Last Answer : (B) Flows outside the tubes
Description : Air is to be heated by condensing steam. Two heat exchangers are available (i) a shell and tube heat exchanger and (ii) a finned tube heat exchanger. Tube side heat transfer area are equal in both ... steam on shell side (D) Shell and tube heat exchanger with air on shell side and steam inside tubes
Last Answer : (B) Finned tube heat exchanger with air outside and steam inside
Description : Describe only construction and working of pipe in pipe heat exchanger. State it’s two applications.
Last Answer : Pipe Heat Exchanger: Construction and Working : In Pipe heat exchanger design, an important factor is the type of flow pattern in the heat exchanger. A pipe heat exchanger will ... more compact. Application : Oil refinery industries , Waste water management, Refrigeration system
Description : Double pipe heat exchangers are used (A) When heat transfer area required is very high (B) When heat transfer area required is very low, i.e. (100-200 ft 2 ). (C) Because it occupies less floor area (D) Because it is less costly
Last Answer : (B) When heat transfer area required is very low, i.e. (100-200 ft 2 )
Description : A metal pipe is 77 cm long. The inner diameter of a cross section is 4 cm, the outer diameter being 4.4cm. -Maths 9th
Last Answer : Let r1 and r2 Inner and outer radii of cylindrical pipe r1 = 4/2 cm = 2 cm r2 = 4.4/2 cm = 2.2 cm Height of cylindrical pipe, h = length of cylindrical pipe = 77 cm (i) curved surface ... CSA of roller = (500 31680) cm2 = 15840000 cm2 = 1584 m2. Therefore, area of playground is 1584 m2. Answer!
Description : Large diameter sewers subjected to external pressure alone, are reinforced A. Near the inner surface of the pipe B. Near the outer surface of the pipe C. Both A. and B. D. With elliptical cage
Last Answer : ANS: D
Description : Venturimeter is used to measure the flow rate of fluids in pipes, when the pipe is in __________ position. (A) Horizontal (B) Vertical (C) Inclined (D) Any
Last Answer : (D) Any
Description : The inner diameter of washer is (A) Equal to the nut size (B) More than the nut size (C) Less than the nut size (D) Independent of the nut size
Last Answer : (B) More than the nut size
Description : Two pipe systems can be said to be equivalent, when the following quantities are same (A) Friction loss and flow (B) Length and diameter (C) Flow and length (D) Friction factor and diameter
Last Answer : Answer: Option A