Description : The general rule for rating refrigeration systems (excepting for CO2 system) is to approximate following h.p. per ton of Refrigeration (a) 0.1 to 0.5 h.p. per ton of refrigeration (b) 0.5 to 0.8 h.p. per ... (c) 1 to 2 h.p. per ton of refrigeration (d) 2 to 5 h.p. per ton of refrigeration
Last Answer : Ans: c
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
Last Answer : Ans: a
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
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
Last Answer : Ans: d
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.
Last Answer : Ans: b
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 : In a boiler enthalpy of water supplied was 2000 kJ/kg. Enthalpy being added by fuel combustion is 3200 kJ/kg. Using first law of thermodynamics, find amount of heat supplied if steam generation rate is 10 tons per hour.
Last Answer : Heat supplied Q = m (h2-h1) …….(Steady flow energy equation for boiler) ; h2=3200 KJ/kg h1=2000 KJ/kg m = 10 Tons /hour = (10 x 1000)/3600 kg/sec = 2.77 Kg/sec Q = 2.77(3200-2000) = 3324 KJ/sec heat supplied for 10 Tons/hr steam generation
Description : In S.J. unit, one ton of refrigeration is equal to (a) 210 kJ/min (b) 21 kJ/min (c) 3.5 kJ/min (d) 2.4 kJ/min
Description : Reducing suction pressure in refrigeration cycle (a) lowers evaporation temperature (b) increases power required per ton of refrigeration (c) lowers compressor capacity because vapour is lighter (d) all of the above.
Description : One ton of the refrigeration is (a) the standard unit used in refrigeration problems (b) the cooling effect produced by melting 1 ton of ice (c) the refrigeration effect to freeze 1 ton of water at ... ice at 0°C in 24 hours (d) the refrigeration effect to produce 1 ton of ice at NTP conditions
Description : One ton of refrigeration is equal to the refrigeration effect corresponding to melting of 1000 kg of ice (a) in 1 hour (b) in 1 minute (c) in 24 hours (d) in 12 hours
Description : The normal heptane(C7H16) is given a rating of ____________ octane number. a) 0 b) 50 c) 100 d) 120
Last Answer : Answer: a Explanation: None.
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 : Production of one ton of dry paper pulp requires about __________ tons of bamboo or wood. (A) 1 (B) 2.5 (C) 5 (D) 10
Last Answer : (B) 2.5
Description : Production of one ton of cement requires about __________ tons of limestone. (A) 0.6 (B) 1.2 (C) 2.2 (D) 3.8
Last Answer : (B) 1.2
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 : A fuel of an octane number rating of 75 matches in knocking intensity as a mixture of a) 75% iso-octane and 25% normal heptane b) 75% normal heptane and 25% iso-octane c) 75% petrol and 25% diesel d) 75% diesel and 25% petrol
Description : If the performance of diesel engine of different sizes, cylinder dimensions and power rating are to be compared, which of the following parameters can be used for such comparison? (a) Swept volume (b) Air fuel ratio (c) Specific brake fuel consumption (d) Volumetric efficiency
Last Answer : Ans :c
Description : The two reference fuel used for cetane rating are (a) Cetane and iso octane (b) Cetane and tetra ethyl lead (c) Cetance and n-heptane (d) Cetane and α- methyl naphthalene
Last Answer : Ans : d
Description : Reference fuels for knock rating of SI engine fuels would include (a) Iso octane alpha methyl naphthalene (b) Normal octance and aniline (c) Isooctance and n octane (d) N heptane and iso octane
Description : Use of gasoline blend like tetraethyl lead in internal combustion engine a. increases the octane rating of the fuel b. allows engine to operate at higher compression ratio c. avoids auto-ignition of fuel d. all of the above
Last Answer : ANSWER d. all of the above
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 : 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 : 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 : 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
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 : The refrigerant for a refrigerator should have (a) high sensible heat (b) high total heat (c) high latent heat (d) low latent heat
Description : The vapour compression refrigerator employs the following cycle (a) Rankine (b) Carnot (c) Reversed Carnot. (d) Brayton
Description : Octane number of petrol normally used in petrol engines is of the order of a. 20-30 b. 40-60 c. 60-70 d. 80-90
Last Answer : ANSWER d. 80-90
Description : Air refrigeration cycle is used in (a) domestic refrigerators (b) gas liquefaction (c)commercial refrigerators (d) Chillers
Description : Air refrigeration cycle is used in (a) domestic refrigerators (b) commercial refrigerators (c) air conditioning (d) gas liquefaction
Description : In a 100 TPD Sponge Iron plant, the sponge iron is fed to the Induction melting furnace, producing molten steel at 88% yield. The Energy consumption details are as follows: Coal Consumption : 130 ... molten steel (product). 3. Total Energy Consumption of Plant in Tons of Oil Equivalent (TOE )
Last Answer : a) Specific Energy Consumption of Induction Melting Furnace Molten Steel Production from the Induction melting furnace per day = 100 x 88/100 = 88 TPD Total Energy Consumption of the Plant = 82400 kWh ... mark c) Total Energy consumption of Plant in ToE = 655864000/107 = 65.586 ToE
Description : COP of a refrigerator drawing 1 kW of power per ton of refrigeration is about (A) 0.5 (B) 3.5 (C) 4.5 (D) 8.5
Last Answer : (B) 3.5
Description : Refrigeration capacity of a household refrigerator may be round about __________ tons. (A) 0.15 (B) 1.5 (C) 4.5 (D) 6.5
Last Answer : (A) 0.15
Description : A refrigerator is working on reversed carnot cycle between temperature of 30°C to –10°C with capacity of 10 tonnes. Calculate. (i) The COP (ii) Define ton of refrigeration (iii) Give the industrial application of refrigeration
Last Answer : (ii) Ton of refrigeration: It is defined as the quantity of heat required to be removed from 1Ton water at 0oC to get ice at 0oC in one day. (iii) Industrial applications of refrigeration ... food stuff such as meat, fruit, fruit juice, vegetables etc. 5. Ice cooling of concrete for dam.
Description : A 5 BHP engine running at full load would consume diesel of the order of A. 0.3 kg/hr B. 1 kg/hr C. 3 kg/hr D. 5 kg/hr
Last Answer : ANSWER ; B
Description : Pick out the wrong statement. (A) A refrigeration cycle violates the second law of thermodynamics (B) Refrigeration cycle is normally represented by a temperature vs. entropy plot (C) In a refrigerator, ... (D) One ton of refrigeration is equivalent to the rate of heat absorption equal to 3.53 kW
Last Answer : (A) A refrigeration cycle violates the second law of thermodynamics
Description : A fuel of cetane number 40 has the same ignition quality as a mixture of a) 40% cetane and 60% alpha methyl naphthalene b) 40% alpha methyl naphthalene and 60% cetane c) 40% petrol and 60% diesel d) 40% diesel and 60% petrol
Last Answer : Answer: a Explanation: A fuel of cetane number 40 has the same ignition quality as a mixture of 40% cetane and 60% alpha methyl naphthalene as cetane number is counted on cetane percentage.
Description : A 40 kW engine has a mechanical efficiency of 80 %. If the frictional power is assumed to be constant with load, what is the approximate value of the mechanical efficiency at 50 % of the rated load? (a) 45% (b) 55 % (c) 65% (d) 75%
Description : The theoretically correct air fuel ratio of a petrol engine is of the order of A. 6:1 B. 10:1 C. 15:1 D. 20:1
Last Answer : ANSWER : C
Description : 2. An electric oven of 2 kW power rating is operated in a domestic electric circuit (220 V) that has a current rating of 5 A. What result do you expect? Explain. -Physics-10
Last Answer : The current drawn by the electric oven can be calculated using the formula P = V × I I = P/V Substituting the values, we get I = 2000 W/220 V = 9.09 A The current drawn by the electric oven is 9.09 A which exceeds the safe limit of the circuit. This causes the fuse to melt and break the circuit.
Description : Allowable pressure on high-pressure side or ammonia absorption system is of the order of (a) atmospheric pressure (b) slightly above atmospheric pressure (c) 2-4 bars (d) 5-6 bars
Description : An engine produces 10 kW brake power while working with a brake thermal efficiency of 30%. If the calorific value of the fuel used is 40000 kJ/kg, then what is the fuel consumption? (a) 1.5 kg/hour (b) 3 kg/hour (c) 0.3 kg/hour (d) 1 kg/hour
Last Answer : Ans :b
Description : In refrigerators, the temperature difference between the evaporating refrigerant and the medium being cooled should be (a) high, of the order of 25° (b) as low as possible (3 to 11°C) (c) zero (d) any value
Description : What is sensible cooling of air? A. the cooling in which sensible heat of air is removed in order to reduce temperature B. the cooling in which temperature of air is reduced without changing in its moisture content C. both a. and b. D. none of the above
Description : Common rail injection system uses injection pressures of the order a) 100-200 bar b) 200-400 bar c) 400-600 bar d) 1500 bar
Last Answer : Answer: d Explanation: Generally, common rail injection system uses injection pressures of the order 1500 bar.
Description : In a SI engine, which one of the following is the correct order of the fuels with increasing detonation tendency? (a) Paraffins, olefins, naphthenes, aromatics (b) Aromatics, naphthenes, paraffins, olefins (c) Naphthenes, olefins, aromatics, paraffins (d) Aromatics, naphthenes, olefins, paraffins
Last Answer : Ans :d
Description : Volumetric efficiency of air compressor is of the order of A. 20% to 30 % B. 40% to 50% C. 60% to 70% D. 70% to 90%
Last Answer : ANSWER : D