Description : The bank of tubes located at the back of the domestic refrigerators are the __________ tubes. (A) Refrigerant cooling (B) Evaporator (C) Condenser (D) Throttling
Last Answer : C) Condenser
Description : Condensing temperature in a refrigerator is the temperature (a) of cooling medium (b) of freezing zone (c) of evaporator (d) at which refrigerant gas becomes liquid
Last Answer : Ans: d
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
Last Answer : Ans: a
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 : 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 : In a refrigeration cycle, the flow of refrigerant is controlled by (a) compressor (b) condenser (c) evaporator (d) expansion valve
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 : In a flooded evaporator refrigerator, an accumulator at suction of compressor is used to (a) collect liquid refrigerant and prevent it from going to compressor (b) detect liquid in vapour (c) superheat the vapour (d) increase refrigeration effect
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
Last Answer : Ans: b
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 : 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).
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 : Domestic refrigerator working on vapour compression cycle uses the following type of expansion device (a) electrically operated throttling valve (b) manually operated valve (c) thermostatic valve (d) capillary tube
Description : The moisture in a refrigerant is removed by (a) evaporator (b) safety relief valve (c) dehumidifier (d) driers
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 : 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 : Where does the lowest temperature occur in a vapour compression cycle ? (a) condenser (b) evaporator (c) compressor (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 : 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 : The higher temperature in vapour compression cycle occurs at (a) compressor discharge. (b) expansion valve (c) evaporator (d) condenser discharge
Description : For ammonia refrigerating systems, the tubes of a shell and tube condenser are made of (a) copper (b) aluminium (c) steel (d) brass
Description : The refrigerant for a refrigerator should have (a) high sensible heat (b) high total heat (c) high latent heat (d) low latent heat
Description : Formation of frost on evaporator in refrigerator (a) results in loss of heat due to poor heat transfer (b) increases heat transfer rate (c) decreases compressor power. (d) can be avoided by proper design
Description : Choose the correct statement (a) A refrigerant should have low latent heat (b) If operating temperature of system is low, then refrigerant with low boiling point should be used (c) Pre-cooling and sub-cooling bf refrigerant are same (d) Superheat and sensible heat of a. refrigerant are same
Description : One of the purposes of sub-cooling the liquid refrigerant is to (a) reduce compressor overheating (b) reduce compressor discharge temperature (c) increase cooling effect (d) ensure that only liquid and not the vapour enters the expansion (throttling) valve
Description : Lowering of condenser temperature (keeping the evaporator temperature constant) in case of vapour compression refrigeration system results in (A) Increased COP (B) Same COP (C) Decreased COP (D) Increased or decreased COP; depending upon the type of refrigerant
Last Answer : (A) Increased COP
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 : The C.O.P. of a domestic refrigerator in comparison to domestic air conditioner will be (a) same (b) more (c) less (d) dependent on weather conditions
Description : Most of the domestic refrigerators work on the following refrigeration system (a) vapour compression (b) vapour absorption (c) carnot cycle (d) electrolux refrigerator
Description : The domestic refrigerator uses following type of compressor (a) centrifugal (b) axial (c) miniature sealed unit (d) piston type reciprocating
Description : The COP of a domestic refrigerator (a) is less than 1 (b) is more than 1 (c) is equal to 1 (d)depends upon the weather conditions.
Description : Rating of a domestic refrigerator is of the order of (a) 0.1 ton (b) 5 tons (c) 10 tons (d) 40 tons
Description : An ideal liquid refrigerant should (A) Not have a sub-atmospheric vapour pressure at the temperature in the refrigerator coils (B) Not have unduly high vapour pressure at the condenser temperature (C) Both (A) and (B) (D) Have low specific heat
Last Answer : (C) Both (A) and (B)
Description : Which of the following is an undesirable characteristic of a refrigerant? (A) It should be non-explosive (B) It should have a sub-atmospheric vapor pressure at the temperature in refrigerator coils (C) Its vapor pressure at the condenser temperature should be very high (D) None of these
Last Answer : (B) It should have a sub-atmospheric vapor pressure at the temperature in refrigerator coils
Description : The formation of frost on cooling coils in a refrigerator (a) increases heat transfer (b) improves C.O.P. of the system (c) increases power consumption (d) reduces power consumption
Description : The common refrigerant in domestic refrigerator is - (1) Neon (2) Oxygen (3) Nitrogen (4) Freon
Last Answer : (4) Freon Explanation: Common refrigerants used in domestic refrigerators are freon, neon and nitrogen. It flows through four components of refrigerator again and again. These four components are cooling chamber, compressor, heat exchanger and expander
Description : The common refrigerant used in domestic Refrigerator is-------? A. Neon B. Spirit C. Freon/Ammonia (Answer) D. Methane
Last Answer : C. Freon/Ammonia (Answer)
Description : The common refrigerant used in domestic refrigerator is?
Last Answer : Freon
Description : The common refrigerant in domestic refrigerator is (1) Neon (2) Oxygen (3) Nitrogen (4) Freon
Description : A domestic refrigerator has a/an __________ cooled condenser. (A) Water (B) Air (C) Evaporative (D) Gas
Last Answer : (B) Air
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 : In milk chilling plant, the usual secondary refrigerant is (a)ammonia (b)sodium silicate (c) glycol (d) brine
Description : The condition of refrigerant before entering the expansion or throttle valve, in a vapour compression system (a) dry vapour (b) wet vapour (c)liquid-vapour mixture (d) high pressure saturated liquid
Description : The coefficient of performance is the ratio of the refrigerant effect to the (a) heat of compression (b) work done by compressor (c) enthalpy increase in compressor (d) all of the above