Description : A certain refrigerating system has a normal operating suction pressure of 10 kg/cm gauge and condensing pressure ofabout 67 kg/cm. The refrigerant used is (a) Ammonia (b) Carbon dioxide (c) Freon (d) Brine
Last Answer : Ans: b
Description : Condenser tubes are not made of (A) Cartridge brass (B) Muntz brass (C) Wood metal (D) Aluminium brass alloy
Last Answer : (C) Wood metal
Description : Which of the following commonly used condenser tube materials has the lowest thermal conductivity? (A) Admiralty brass (B) Stainless steel (C) Aluminium brass (D) Titanium
Last Answer : (B) Stainless steel
Description : In surface condensers write role of (i) Water tubes (ii) Shell (iii) Baffle plate (iv) Tube sheet
Last Answer : Function of parts in surface condensers 1. Water tubes- Cooling water flows through it , for convective heat transfer to occur with steam outside the tubes 2. Shell- Outer body, all components are ... and improves heat transfer 4. Tube sheet- All tubes are supported at the end in tube sheet
Description : Which of the following is the most suitable material of construction for the condenser tubes, where the cooling medium is brine (salty water)? (A) Aluminium (B) Copper (C) Titanium (D) Stainless steel
Last Answer : Option C
Description : Steam condenser tubes are made of admiralty brass, in which percentage of zinc & copper are __________ respectively. (A) 70 & 30 (B) 30 & 70 (C) 50 & 50 (D) 90 & 10
Last Answer : (A) 70 & 30
Description : The bank of tubes at the back of domestic refrigerator are (a) condenser tubes (b) evaporator tubes (c) refrigerant cooling tubes (d) capillary tubes
Last Answer : Ans: a
Description : Cooling water is required for following equipment in ammonia absorption plant (a) condenser (b) evaporator (c) condenser and absorber (d) condenser, absorber and separator (rectifier).
Last Answer : Ans: d
Description : The suction pipe diameter of refrigerating unit compressor in comparison to delivery side is (a) bigger (b) smaller (c) equal (d) smaller/bigger depending on capacity
Description : Tubes of multiple effect evaporator used for concentration of sugar cane juice are made of (A) Nickel (B) Copper (C) Stainless steel (D) Brass
Last Answer : (B) Copper
Description : Choose the wrong statement (a) Temperature of medium being cooled must be below that of the evaporator (b) Refrigerant leaves the condenser as liquid (c) All solar thermally operated absorption systems are capable only of intermittent operation (d) frost on evaporator reduces heat transfer
Description : Dip stick used for measuring the level of petro fuels (e.g. petrol, diesel, fuel oil etc.) in the storage tank is usually made of (A) Brass (B) Copper (C) High carbon steel (D) Aluminium
Last Answer : (A) Brass
Description : Temperature of hot gases flowing in a pipe is measured by a thermocouple inserted in the thermal well. The thermal well made of __________ will facilitate the most accurate measurement of the temperature. (A) Copper (B) Steel (C) Aluminium (D) Brass
Last Answer : Option A
Description : Which of the following materials may prove unsuitable for handling acetic acid (glacial & anhydrous) at 40°C? (A) Silicone rubber, teflon, porcelain and wood (B) Nickel, monel, stainless steel and graphite (C) Aluminium, copper, high silicon iron (D) Brass, cast iron, mild steel and tin
Last Answer : (D) Brass, cast iron, mild steel and tin
Description : Which of the following materials has the least scrap value? (A) Aluminium (B) Stainless steel (C) Brass (D) Copper
Last Answer : Option B
Description : The material generally used for armour of high voltage cables is (a) aluminium (b) steel (c) brass (d) copper
Last Answer : (b) steel
Description : Neutraliser tank used for reacting nitric acid with ammonia for the production of ammonium nitrate is made of (A) Aluminium (B) Stainless steel (C) High silicon (14%) iron (D) Copper
Description : In jet refrigerators, the refrigerating fluid is practically always (A) Water (B) Ammonia (C) Freon (D) Brine
Last Answer : (A) Water
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
Description : The C.O.P. of a refrigeration cycle with lowering of condenser temperature, keeping the evaporator temperatureconstant, will (a) increase (b) decrease (c) may increase or decrease depending on the type of refrigerant used (d) remain unaffected
Description : The C.O.P of a refrigeration cycle with increase in evaporator temperature, keeping condenser temperature constant, will (a) increase (b) decrease (c) remain unaffected (d) may increase or decrease depending on the type of refrigerant used
Description : Where does the lowest temperature occur in a vapour compression cycle ? (a) condenser (b) evaporator (c) compressor (d) expansion valve
Description : In a refrigeration cycle, the flow of refrigerant is controlled by (a) compressor (b) condenser (c) evaporator (d) expansion valve
Description : If the evaporator temperature of a plant is lowered, keeping the condenser temperature constant, the h.p. of compressorrequired will be (a) same (b) more (c) less (d) more/less depending on rating
Description : If a heat pump cycle operates between the condenser temperature of +27°C and evaporator temperature of - 23°C,then the Carnot COP will be (a) 0.2 (b) 1.2 (c) 5 (d) 6
Description : In vapour compression refrigeration system, refrigerant occurs as liquid between (a) condenser and expansion valve (b) compressor and evaporator (c) expansion valve and evaporator (d) compressor and condenser
Last Answer : Ans: c
Description : A refrigeration cycle operates between condenser temperature of + 27°C and evaporator temperature of- 23°C. TheCarnot coefficient of performance of cycle will be (a) 0.2 (b) 1.2 (c) 5 (d) 6
Description : In refrigerator, liquid receiver is required between condenser and flow controlling device, if quantity of refrigerant for system is (a) less than 2 kg (b) more than or equal to 3.65 kg (c) more than 10 kg (d) there is no such consideration
Description : The higher temperature in vapour compression cycle occurs at (a) compressor discharge. (b) expansion valve (c) evaporator (d) condenser discharge
Description : For better COP of refrigerator, the pressure range corresponding to temperature in evaporator and condenser must be (a) small (b) high (c) equal (d) anything
Description : Presence of moisture in a refrigerant affects the working of (a) compressor (b) condenser (c) evaparator (d) expansion valve.
Description : In vapour compression cycle the condition off refrigerant is dry saturated vapour (a) after passing through the condenser (b) before passing through the condenser (c)before entering the expansion valve (d) before entering the compressor
Last Answer : Ans: D
Description : In vapour compression cycle the condition of refrigerant is superheated vapour (a) after passing through the condenser (b) before passing through the condenser (c) after passing through the expansion or throttle valve (d) beforeentering the expansion valve
Description : In vapour compression cycle, the condition of refrigerant is high pressure saturated liquid (a) after passing through the condenser (b) before passing through the condenser (c) after passing through the expansion or throttle valve (d) before entering the expansion valve
Description : In vapour compression cycle, the condition of refrigerant is very wet vapour (a) after passing through the condenser (b) before passing through the condenser (c) after passing through the expansion or throttle valve (d) before entering the expansion valve
Description : In vapour compression cycle, the condition of refrigerant is saturated liquid (a) after passing through the condenser (b) before passing through the condenser (c) after passing through the expansion throttle valve (d) before entering the expansion valve
Description : Describe any two sources of air leak in surface condenser. Also describe effect of air leak on latent heat of steam and cooling water requirements.
Last Answer : ✓ The main sources of air leakage found in condenser are given below: 1) There is leakage of air from atmosphere at the joint of the parts which are internally under a pressure less ... hence evaporation enthalpy of steam increases therefore more amount of cooling water required in the condenser.
Description : Identify modes of heat transfer involved applications with brief explanation. (1) Radiator of automobile (2) Condenser of domestic refrigerator.
Last Answer : Modes of heat transfer Automobile radiator-A radiator is a type of heat exchanger. It is designed to transfer heat from the hot coolant that flows through it to the air blown through ... of heat transfer plays very important deciding factor transferring heat from condenser tube to atmosphere.
Description : Explain construction and working of shell and tube type heat exchanger. A ice plant producing 2000 Kg ice per day required the condenser. Suggest the type of condenser with justification.
Last Answer : Shell and tube heat exchanger consist of a bundle of round tubes placed inside the cylindrical shell.Tube axis parallel to that of shell. One fluid inside the tubes while the other over ... of heat rejection by the evaporation of water into an air stream traveling across the condensing coil.
Description : The pump is mostly made of: e) Aluminium c) Brass f) Copper d) Plastic
Last Answer : Aluminium
Description : The pump is mostly made of: A. Aluminium B. Copper C. Brass D. Plastic
Description : Locomotive boiler tubes are made of __________ alloys. (A) Arsenic copper (B) Magnesium (C) Aluminium (D) Nickel
Last Answer : (A) Arsenic copper
Description : Engine pistons are usually made of aluminium alloy because it A. is lighter B. wears less C. Stronger D. absorbs shocks
Last Answer : ANSWER : A
Description : Engine pistons are usually made of aluminium alloy as it a. is lighter b. wears less c. absorbs shocks d. is stronger
Last Answer : ANSWER a. is lighter
Description : Condensing film co-efficient for steam on horizontal tubes ranges from 5000 to 15000 Kcal/hr.m2 .°C. Condensation of vapor is carried out inside the tube in a shell and tube heat ... drop through the exchanger is desired (D) Temperature of the incoming vapor is very high
Last Answer : (B) Supersaturated
Description : Pick out the wrong statement: (A) The capacity of an evaporator is reduced by the boiling point elevation (B) Corrosive liquid is normally passed through the tubes in a ... recompression evaporator (D) Heat sensitive materials should be concentrated in high pressure evaporators
Last Answer : (D) Heat sensitive materials should be concentrated in high pressure evaporators
Description : The main function of baffles provided in a shell and tube heat exchanger is to (A) Facilitate the cleaning of outer tube surface (B) Enhance turbulence (C) Hold the tubes in position (D) All 'a', 'b' & 'c'
Last Answer : (B) Enhance turbulence
Description : Vibrations in the tubes of a shell and tube heat exchanger is induced due to the (A) Flow of fluid on the tube and shell sides (B) Oscillations in the flow of shell/tube sides fluid (C) Vibrations ... piping and/or supports due to external reasons (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)