Question Bank Eme

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Question Bank Elements of Mechanical Engineering

Dept.of Mech.Engg. Page 1

Unit-1 Fuels and steam

Objective questions

1.

The energy derived from the fuels existing in the earth is known as

A) Income energy B) Capital energy C) Internal energy D) None

2. The energy contained in a chemical system by virtue of, the motions of and forces between theindividual atoms and molecules of the system is

A) Kinetic energy B) Potential energy C) Internal energy D) External energy

3. Which of the following is celestial source of energy?

A) Electromagnetic, B) Gravitational C) Particle D) All of the above

4. The energy coming from the outer space to the earth is

A) Celestial energy B) Internal energy C) Capital energy D) External energy

5. Which of the following is true about Renewable energy sources?

A) They are inexhaustible B) They are available at free of cost

C) Initial cost is high but maintenance cost is low D) All of the above

6. Which of the following is not true about Non- renewable energy sources?

A) They are exhaustible B) Both initial and maintenance costs are less

C) They are not available at free of cost D) None

7.

Which of the following is a photosynthesis process which is the source of all fossil fuels and the

food?

A) Helio thermal process B) Helio electrical process

C) Helio chemical process D) Fuel cell system

8. A process in which using the principle of photovoltaic effect the solar energy is directly

converted into electrical energy is,

A) Helio electrical B) Helio thermal C) Helio chemical D) None

9. Flat- plate collector of converting the solar energy into useful form is an example of

A) Helio chemical process B) Helio electrical processC) Fuel cell system D) Helio thermal process.

10.Which of the following is conventional (Non - renewable) source of energy?

A) Wind energy B) Bio energy C) Nuclear energy D) Tidal energy

11.Which of the following is not a conventional source of energy?

A) Hydel energy B) Tidal energy C) Natural gas D) None


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23.A two phase mixture of entrained water molecules and steam in thermal equilibrium at the

saturation temperature corresponding to a given pressure is

A)

Dry Steam B) Saturated water C) Superheated Steam D) Wet Steam

24.

Quality of wet steam is decided byA) Its temperature B) Pressure C) Dryness fraction D) None

25.A condition of steam where there are no water molecules entrained in it is defined as

A) Dry Steam B) Superheated Steam C) Wet Steam D) None

26.Dryness fraction for dry steam is

A) >1 B) =1 C) 1 B) =1 C) 1 B) =1 C) In between 0 &1 D) None

29.The sum of internal energy and the product of pressure and volume is,

A) Enthalpy B) Sensible heat C) Latent heat D) None

30.Specific volume of super heated steam (Vsup), with usual notations is

A) = Vgx B) Sensible heat C) Latent heat D) None

31.

The energy required to change the phase is known as

A) Internal energy B) True latent heat

C) External work of evaporation D) None

32.The net energy present in the steam is called as

A) Internal energy B) True latent heatC) External work of evaporation D) None

33.Steam is used

A) Only for power generation B) Only for process heatingC) For both power generation and process heating D) None

34.Which of the following is an example for fire tube boiler?

A) Stirling boiler B) Yarrow boiler

C) Babcock and Wilcox boiler D) Cochran boiler

35.Which of the following is an example for water tube boiler?

A) Lancashire boiler B) Cornish boiler C) Stirling boiler D) Cochron boiler


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36.Lancashire boiler is a

A) Horizontal, internally fired boiler B) Vertical, internally fired boilerC) Horizontal, externally fired boiler D) Vertical, externally fired boiler

37.

Babcock and Wilcox boiler is aA) Horizontal, internally fired boiler B) Horizontal, externally fired BoilerC) Vertical, Internally fired Boiler D) Vertical, externally fired Boiler

38.The boiler widely used in the process industries to generate steam is

A) Cornish boiler B) Stirling boiler

C) Babcock and Wilcox boiler D) Lancashire boiler

39.The boiler used in thermal power stations for generating large quantities of steam at highpressures is

A) Lancashire boiler B) Cornish boiler C) Babcock and Wilcox boiler D) None

40. In Babcock and Wilcox Boiler, Sediments present in the water due to heavier specific gravity willsettle down in

A) Mud box B) Blow off pipe C) Moving Grate D) None

41.Which of the following boiler mounting is used as a safety device?

A) Feed check Valve B) Fusible plug C) Blow-off cock D) Pressure gauge

42.Which of the following is tine with reference to Babcock and Wilcox boiler

A) It is a stationary water tube boiler B) It is horizontal type boiler

C) It is externally fired boiler D) All of the above

43.The function of accessories in a boiler is

A) Operation and safety of boiler B) Safety of boilerC) To increase the efficiency D) All the above

44.

The function of mountings in a boiler is

A) Operation and safety of boiler B) Safety of boiler

C) To increase the efficiency D) All of the above

45.The function of mountings and accessories in a boiler is

A) Operation of the boiler B) Safety of boilerC) To increase the efficiency D) All of the above

46.The excess steam from the boiler can be suddenly released by

A) Steam stop valve B) safety valve C) Blow off valve D) Feed check valve

47.To regulate the flow of steam from the boiler, is used


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A) Safety valve B) Peed check valve C) Steam stop valve D) Blow off valve

48.The function of feed check valve in a boiler is

A) To regulate the rate of flow of feed waterB)To prevent the escape of the water from the boiler

C)

Both the aboveD) None

49.

________ is used to remove periodically the sediments collected at the bottom of theboiler while in operation

A) Blow off valve B) Fusible plug C) Steam separator D) None

50.Which of the following mounting is used to extinguish the fire in the furnace of the boiler?

A) Safety valve B) Blow-off cock C) Chimney D) Steam Trap

51.The Boiler accessory that is used to recover heat from the exit gases is

A) Economizer B) Super heater C) Chimney D) Steam trap

52. In a boiler, to increase the temperature of the steam above the saturation temperature is used

A) Economizer B) Super heater C) Steam trap D) Steam separator

53.Which of the following boiler accessory is used to drain off the condensed water accumulated inthe steam pipe without allowing the steam to escape through it

A) Feed pump B) Steam separator C) Super heater D) Steam trap

54. In a power plant which of the following boiler accessory is installed very close to the steamturbine on the main supply pipe?

A) Steam trap B) Super heater C) Steam separator D) Air Pre heater

55.Which of the following boiler accessory is installed between the economizer and the chimney

A) Air pre heater B) Super heater C) Steam separator D) Steam trap

01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20

B C D A D B C A D C B A D C B D A B B C

21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

B A D C A B D C A B B A C D C A B D C A

41 42 43 44 45 46 47 48 49 50 51 52 53 54 55

B D C A D B C C A C A B D C A

1. Find the total enthalpv of 0.6 kg of steam with an initial dryness fraction of 0.7 is heated atconstant of 7 bar till its temperature rises to 250C. Assume C= 2.25 KJ/kgK. From steam table,

at 7679.1 KJkg. h1 2064.9 KJkg. Tsat, 165C.2. Explain with a neat sketch, the working principle of a Lancashire boiler.


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ENERGY RESOURCES

1. Classify different sources of energy with suitable examples.

2. Distingwish between

(a)Renewable and nonrenewable energy sources.(b)Conventionl and nonconventional energy sources.

and give the examples for the above types of energy sources.3. What are the advantages & disadvantages of renewable and non renewable/conventional

and non conventional sources of energy?

4. With a neat schematic sketch, explain the harnessing (obtaining power) of the following

types of nonconventional energy resources.

(a) Solar energy(b) Wind energy

(c) Geothermal energy

(d) Tidal energy(power)

(e) Ocean thermal energy(OTEC)5. What are the advantages and dis advantages of each of the above type of energy

resources?

STEAM AND ITS PROPERTIES

1. Explain the formation of steam at constant pressure with suitable sketches.2. Define the following terms :

(i) Sensible heat, (ii) Latent heat, and (iii) Total heat (Enthalpy) of evaporation.

3. Explain the following terms:(i) Wet steam, (ii) Dry saturated steam, and (iii) Superheated steam.

4. Define the following :

(i) Dryness fraction, and (ii) Degree of superheat

5.

What is the difference between dry steam and wet steam ?6. List out the advantages of superheated steam.

7. What do you mean by

(i) Specific Volume (b) External work during evaporation and (c) Internal energy?8. What is the use of Steam table?

STEAM BOILERS

1. What is a steam boiler ? How are boliers classified?

2. Explain the principles of fire tube and water tube boilers.

3. Differentiate between the following:

(i) Internally fired and externally fired boilers.(ii) Fire tube and water tube boilers.

4.

Describe with the aid of neat labelled diagram, the construction and working of

(i) Lancashire (fire tube) boiler(ii) Babcock and Wilcox (Water tube) boiler

Indicating the path of the flue gases

5. What are the merits and de-merits of water tube boilers over fire tube boilers?6. Differentiate between boiler mountings and boiler accessories

7. State the function of the following boiler mountings


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(i) water level indicator, (ii) steam stop valve,

(iii) Feed check valve, (iv) Blow-off cock,

(v) Fusible plug, (vi) safety valve,(vii) Pressure gauge

8. State the function of the following boiler accessories :

(i) Economiser, (ii) Air pre-heater, (iii) Superheater,(iv) Steam separator, (v) Feed pump, (vi) Steam trap.

Unit-2 Turbines and I.C. engines and pumps

1. Prime mover is a device which converts the available natural source of energy into _____ of

motion, to drive the other machines.

A) Electrical energy B) Mechanical EnergyC) Heat energy D) Kinetic energy

2.

An ideal prime mover, used to drive the electric generators in thermal power plants to generateelectric power is

A) Steam engine B) Internal combustion engineC) Steam turbine D) Gas turbine

3. In convergent divergent nozzle the steam which will enter at high pressure, low velocity will exitwith

A)

Low pressure, high velocity jet of steamB)

High pressure, low velocity jet of steam

C)Low pressure, low velocity jet of steamD)High pressure, high velocity jet of steam

4. In convergent divergent nozzle, the loss in the enthalpy of the steam is equal to

A) Decrease in velocity of steam B) Increase in velocity of steamC) Velocity of steam D) None of the above

5. In impulse turbine

A)The steam is initially expands in a nozzle from low pressure to high pressure

B)The steam does not initially expand in the nozzle C)The steam is initially expands in a nozzle form high pressure to low pressureD)None of the above

6.

Parsons turbine is also called

A) Impulse steam turbine B) Gas turbine

C) Water turbine D) Reaction steam turbine

7. In a reaction turbine, the high pressure steam continuously expands

A)Successively in both the fixed and moving bladesB)In fixed blades


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C)In moving bladesD)None

8. The net force acting on the moving blades of a reaction turbine is equal to

A) Centrifugal force B) Vector sum of the centrifugal and reaction forces

C)

Reaction force D) Vector difference of centrifugal and reaction forces

9. In case of reaction steam turbine,

A) There is enthalpy drop only in fixed blades and moving bladesB) There is enthalpy drop only in fixed bladesC) There is enthalpy drop only in moving blades

D) None of the above

10.The pressure on the two sides of the impulse wheel of a steam turbine

A) Increases from one side to other side B) Is sameC) Decreases from one side to other D) None

11.

In case of impulse steam turbine,

A)

There is enthalpy drop in fixed and moving blades

B) There is enthalpy drop in moving bladesC) There is enthalpy drop in nozzlesD)None of the above

12.

Curtis turbine is

A)Reaction steam turbine

B)Pressure velocity compounded steam turbineC)Pressure compounded impulse steam turbine

D)Velocity compounded impulse steam

13.

Utilization of the high pressure energy of the steam by expanding it in successive stages is called,

A) Closed cycle gas turbine B) Compounding

C) Impulse turbine D) Reaction turbine

14.

The high velocity steam particles enter in the turbine blades, which gives rise to

A) Change in momentum B) Change in direction of motionC) Change in kinetic energy D) None

15. In case of impulse water turbine, the entire hydro energy is converted into kinetic energy bypassing the water through

A) Tail race B) Runner C) Penstock D) None

16.

An impulse water turbine requires ______at the inlet of the turbine

A) High head and high discharge B) Low head and high discharge

C) Constant amount of pressure energy D) High head and low discharge

17. In case of impulse water turbine, _____ is converted into kinetic energy before it is passed on to


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the turbine wheel

A) Part of the pressure energy B) Whole of thepressure energyC) Constant amount of pressure energy D) None

18. In case of reaction water turbine, _____ is converted into kinetic energy before it is passed on to

the turbine wheelA) Part of the pressure energy B) Whole of the pressure energyC) Constant amount of pressure energy D) None

19. In case of impulse water turbine, the pressure of the water will be _____ as it flows over themoving blades

A) Continuously decreases B) Continuously increasesC) Atmospheric D) None

20. In case of reaction turbine, the pressure of the water will be ___ as it flows over the movingblades

A) Continuously decreases B) Continuously increasesC) Atmospheric D) None\

21. In case of reaction water turbine, water discharges to the tail race

A) Directly from the turbine wheel B) Through draft tubeC) Through spiral casing D) Through guide blade

22.Francis turbine is

A) A reaction turbine B) An impulse turbineC) May be a reaction or an impulse turbine D) None of the above

23.

Pelton wheel is aA) Low head impulse turbine B) Medium head impulse turbineC) High head impulse turbine D) Reaction turbine

24.Francis turbine is

A) A medium head reaction turbine B) A high head reaction turbineC) A low head reaction turbine D) An impulse turbine

25.Kaplan turbine is a

A) Low head impulse turbine B) Low head reaction turbine

C) Medium head reaction turbine D) High head reaction turbine

26.

Which of the following is a high head, tangential flow, horizontal shaft, impulse turbine

A) Francis turbine B) Kaplan turbine C) Thomson turbine D) Pelton wheel

27.Velocity compounding comprises of

A)Alternate rows of fixed nozzles and moving blades in series

B)Alternate rows of fixed blades and moving blades in seriesC)

One set of nozzles and two or more rows of moving blades in seriesD)Only moving blades in series


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37.Thermal efficiency of a steam turbine when compared to a heat engine is,

A) Low B) High C) Same D) None

38. Mechanical efficiency of a gas turbine when compared to an internal combustion engine is,

A) Low B) High C) Same D) None

39.The cross section of a draft tube in a turbine

A) Gradually decreases towards the outlet B) Is uniformC) Gradually increases towards the outlet D) None

40. Kaplan turbine is a

A) Low head impulse turbine B) Medium head impulse turbine

C) Low head reaction turbine D) High head impulse turbine

41.In case of impulse turbines steam expands

A) Completely in the nozzle B) Completely in the moving bladesC) Completely in the fixed blades D) None

42.Propeller turbine is the other name of

A) Kaplan turbine B) Francis turbine C) Pelton wheel D) Gas turbine

01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20

B C A B C D A B A B C D B A C D B A C A

21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

B A C A B D C A D D B C D A B A C C A A

STEAM TURBINE

1. Define a steam turbine and state its fields of application.

2. How are steam turbines classified?

3. Describe the principle and working of impulse turbine with a neat sketch.4.

Describe the principle and working of a reaction turbine with a neat sketch.

5. State the differences between an impulse turbine and reaction turbine.

6. Explain the working principle of Delavals turbine with a neat sketch

7. Explain the working principle of Parsons turbine with a neat sketch

8.

Sketch and explain the working of reaction steam turbine with the help of pressure andvelocity profile diagram.

GAS TURBINE

1. Explain the principle of operation of a gas turbine?

2. How the gas turbines are classified.


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3. Draw a constant pressure open cycle gas turbine diagram and explain its working.

4. Explain the working principle of a closed cycle gas turbine with a line diagram

5. Differentiate between open cycle and closed cycle gas turbines6. What are the advantages and disadvantages of open cycle over closed cycle gas turbine?

7. What are the advantages of gas turbines over IC engines?

WATER TURBINE

1. Explain the principle of operation of hydraulic turbines

2. How the hydraulic turbines are classified?3. Differentiate between impulse and reaction water turbine.

4. Explain the working of Pelton wheel (Impulse turbine) with a neat sketch.

5. With a neat sketch, explain the working of a Kaplan (Reaction) turbine6. Describe the working of Francis turbine, with a neat sketch with parts being labeled. Also

mention the function of each part.

7. Differentiate between Francis turbine and Kaplan turbine.

8. List the important parts of a Pelton wheel and explain their functions.

I.C. ENGINES

1. In a heat engine, conversion of energy takes place from

A)Heat energy to Mechanical energy.B)Solar energy to heat energy.C)Mechanical energy to heat energy.

D)Electrical energy to heat energy.

2. The most common example of external combustion engine is

A) Petrol engine B) Gasoline engine C) Stem engine D) Diesel engine

3. In _____, the combustion of fuel takes place inside the working cylinder.

A) Steam turbine B) Diesel engineC) Steam engine D) Closed cycle gas turbine.

4. The heart of the engine is

A) Valve B) Cylinder C) Connecting rod D) Piston

5.

The primary function of engine cylinder is to

A) Contain the working fluid under pressure

B) Guide the pistonC) Receive impulse from the expanding gasD) Transmit the push and pull from piston pin to the crank pin.

6.

The power developed by the combustion of the fuel is transmitted to the crankshaft by the

A) Valves B) Piston C) Cylinder D) Flywheel

7. A link that connects the piston and the crank shaft by means of pin joints is


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A) Piston rings B) Cylinder head C) Crank D) Crank connecting rod

8. One end of the cylinder is closed by means of

A) Valves B) A piston C) Removable cylinder head D) Crankshaft

9.

The cylinder head of I.C engine containsA) Inlet valve only B) Exhaust valve onlyC) Either inlet or outlet valve D) Both inlet and outlet valve

10.Maintaining a pressure tight seal between piston and the cylinder liner is the function of

A) Compression rings B) Oil control rings C) Valves D) Cams

11.The rectilinear motion of the piston is converted into rotary motion of the crank shaft by

A) Piston rings B) Connecting rod C) Fly wheel D) Crank case

12.The inside diameter of the cylinder is called

A) Stroke B) Clearance C) Bore D) Pitch

13.The volume contained in the cylinder above the top of the piston, when the piston is at TDC

is called ______

A) Clearance volume B) Swept volume

C) Stroke volume D) Specific volume

14.Compression ratio of is the ratio of

A) Total cylinder volume to the clearance volumeB) Clearance volume to the total volumeC) Stroke volume to the clearance volumeD) Total cylinder volume to stroke volume

15.For a given bore d and the stroke length l, the swept volume can be calculated by using theformula

A) (/4).d.l B) .d.l C) (/2).d2.l D) (/4).d2.l

16. In a 4 stroke engine, the four operations namely suction, compression, expansion and exhaustare completed in the number of revolutions of crankshaft equal to

A) Four B) Three C) Two D) One

17. In a 4 stroke engine, the sequence (order) in which the 4 strokes completes.

A) Suction, Exhaust, Expansion & CompressionB) Suction, Compression, Expansion & ExhaustC) Expansion, Compression, Suction & ExhaustD) Compression, Expansion, Exhaust & Suction

18.Which of the following is an example of SI Engine?


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A) Petrol Engine B) Diesel Engine C) Gas Engine D) None of the above

19.Which of the following is an example of SI Engine?

A) Petrol Engine B) Diesel Engine C) Gas Engine D) None of the above

20.

Otto cycle is also known asA) Constant pressure cycle B) Constant temperature cycleC) Constant density cycle D) constant volume cycle

21.The petrol engine works on the principle of theoretical

A) Petrol Cycle B) Otto cycle C) Diesel cycle D) Carnot cycle

22. In SI engines, heat is added atA) Constant volume B) Constant pressureC) Constant temperature D) Constant density

23.

In 4-stroke petrol engine ______ Enters during the suction strokeA) Only Petrol B) Only Air C) Petrol & Air D) Diesel & Air

24.During the compression stroke of 4 stroke engines

A) Both inlet and exhaust valves openB) Both inlet and exhaust valves closesC) Inlet valve opens and exhaust valve closesD) Inlet valve closes and exhaust valve opens

25.The compression ratio in SI engine ranges from

A) 1:7 to 1:11 B) 1:11 to 1:22 C) 1:7 to 1:22 D) 1:11 to 1:30

26.

The diesel engine works on the principle of theoretical

A) Otto cycle B) Petrol cycle C) Carnot cycle D) Diesel cycle

27.Diesel cycle is also known as

A) Constant density cycle B) Constant pressure cycleB) Constant temperature cycle D) Constant volume cycle

28. In CI engines, heat is added at

A) Constant pressure B) Constant temperature

C) Constant density D) Constant volume

29. In four stroke diesel engine, during suction stroke ______ enters the engine cylinder

A) Air B) Diesel C) Air & Diesel D) None

30.

The compression ratio of CI engines ranges from

A) 1:7 to 1:11 B) 1:7 to 1:20 C) 1:20 to 1:22 D) 1:11 to 1:20


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A) (a.l)/s B) (a.s)/l C) (s.l)/a D) a/(l.s)

45.The brake power of an engine is always _____ the indicated power

A) Equal to B) Less than C) Greater than D) Reciprocal of

46. If the brake power and the mechanical efficiency of a single cylinder diesel engine is 75kW

and 90% respectively, then the indicated power developed is

A) 83 kW B) 83.33 kW C) 67.5 kW D) 74.1 kW

47. If the brake thermal efficiency and indicated thermal efficiency of a petrol engine is 27.27%and 31.17% respectively then its mechanical efficiency will be

A) 3.9% B) 58.44% C) 8.5% D) 87.5%

48.A certain engine produces 10kW indicated power. If its mechanical efficiency is 80% thefrictional power lost is

A) 2kW B) 8kW C) 9.2kW D) 10.8kW

49.A 2-Stroke engine delivers 5000kW using 1000kW to overcome frictional losses. Its

mechanical efficiency will be

A) 20% B) 83% C) 38% D) 50%

50.The brake thermal efficiency is equal to

A) Mechanical efficiencyIndicated thermal efficiencyB) Mechanical efficiency X Indicated thermal efficiencyC) Mechanical efficiency / Indicated thermal efficiency

D) Mechanical efficiency + Indicated thermal efficiency

01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20

A A B B A B D C D A B C A A D C B A C B

21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

D A C B A D B A A C B A C C A B A C A C

41 42 43 44 45 46 47 48 49 50

B D A B B B D A B B

1.

What is an engine?2. What is a Heat engine? How it is classified?

3. What is the difference between IC engines and EC engines?4. Give advantages of two stroke engine over four stroke engine.5. How the IC engines are classified?6. Enumerate the various parts of an IC engine.

7. A 4-cylinder two-stroke petrol engine develops 30KW at 2500 rpm. The mean effective pressureon each piston is 8 bar and mechanical efficiency is 80%. Calculate the diameter and stroke ofeach cylinder, stroke to bore ratio 1.5. Also calculate the specific fuel consumption if brake


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thermal efficiency is 28%. The calorific value of fuel is 43900KJ/kg.8. Define the following terms:

(i) Indicated Power(ii) Frictional power(iii) Brake power(iv) Mechanical efficiency

(v)

Stroke(vi) Top and bottom dead centers(vii) Compression ratio(viii) Mean effective pressure

9. List and mention the function various parts of an IC engine.10.A four stroke diesel engine has a piston diameter 250mm and stroke 400mm. The mean effective

pressure is 4 bar and the speed is 500rpm. The diameter of the brake drum 1000mm and theeffective brake load is 400 N. Find indicated power, Brake power and frictional power.

11.A gas engine working on a four stroke cycle has a cylinder diameter of 0.25 m and length ofstroke of 0.45 m and is running at 180 r/min. Its mechanical efficiency is 80% when mean

effective pressure is 6.5 bars. Find indicated power, brake power and friction power. What is thefuel consumption rate (kg/hour) and brake specific fuel consumption (kg/kWh) if the energy

content of the fuel used is 42000 kJ/kg and brake thermal efficiency is 25%.12.A single cylinder 4-S I.C. engine has a swept volume of 6 litres and runs at a rated speed of 300

rpm. At full load, the torque developed was measured with a belt dynamometer whose pulley

diameter is 1m. The tension in the tight side and slack side of the belt is 700N and 300Nrespectively. 4 kg of fuel was consumed in one hour. The indicated mean effective pressure is 6

bar and the C.V of the fuel is 42000 kJ/kg. Calculate the brake power, IP, mechanical efficiency,

indicated thermal efficiency, brake thermal efficiency and brake specific fuel consumption.13.

A single cylinder 4-stroke I.C. engine has bore of 180mm, stroke of 200mm and a rated speed of

300 rpm. Torque on the brakedrum is 200 N-m and mean effective pressure is 6bar. It consumes4kg of fuel per hour. The calorific value of fuel is 42000Kj/Kg. Determine BP, IP, brake thermalefficiency and mechanical efficiency.

14.The following observations were recorded during a test on 4-stroke diesel engine: Bore=200 mm,

Stroke=250 mm, mean effective pressure= 0.6MPa, brake drum diameter= 1.2m, Net brake load=500N, speed of crank shaft = 600 rpm. Find, i)Indicated power, ii) Brake power iii) Friction

power iv) Mechanical efficiency.15.The following observations were recorded during a test on 4-stroke diesel engine: Bore=25 cm,

Stroke=40 cm, speed of crank shaft = 250 rpm, Net load on the brake drum=700N, Diameter ofbrake drum = 2m, Indicated mean effective pressure = 6 bar. Determine, i) BP ii) IP iii)FP iv)Mechanical efficiency.

16.A single cylinder, 4-stroke, diesel engine develops indicated power of 30 KW at 300 rpm. Theindicated mean effective pressure is 6.5 bar. The piston speed is 180 m/min. Determine the stroke

and diameter of the cylinder. Also find brake specific fuel consumption, if the mechanical

efficiency is 80% and indicated thermal efficiency is 30%. Take the calorific value of

diesel as 40,000 kJ/kg.

17.

The following observations were recorded during a test on 4-stroke diesel engine: Bore=25 cm,Stroke=40 cm, speed of crank shaft = 250 rpm, Net load on the brake drum=70 kg, Diameter of

brake drum = 2m, Indicated mean effective pressure = 6 bar diesel oil consumption = 0.1 m3/min,

specific gravity of fuel = 0.78, CV of fuel = 43900kJ/kgK. Determine i) IP ii) BP iii)FP iv)Mechanical efficiency v) Brake thermal efficiency vi) Indicated thermal efficiency.

18.Following data are collected from a 4-stroke single cylinder oil engine at full load.


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Bore =200 mm, stroke = 280 mm, speed = 300 rpm. Indicated mean effective pressure=5.6 bar,torque on the brake drum = 250 N.m. Oil consumed 4.2 kg/hour. Calorific value of oil 41,000

kJ/kg. Determine mechanical efficiency, indicated thermal efficiency and brake thermalefficiency.

19.Explain the working of following IC engines With the aid of respective p-v diagram(i) 4 Stroke cycle Diesel engine.

(ii)

4 Stroke cycle Petrol engine.(iii) 2 Stroke cycle petrol engine

20.Differentiate between(i) 2 Stroke and 4 stroke engines(ii) Petrol (SI) engine and Diesel (CI) engine.

1. A four stroke diesel engine has a bore diameter of 250 mm and stroke length

400 mm. the net mean effective pressure is 4 bars and speed is 500 rpm. The

diameter of the brake drum is 1000 mm and the effective brake load is 400 N.

find the (i) Indicated power, (ii) Brake power, (iii) Mechanical efficiency and(iv) frictional power.

Answers: IP: 32.66 kW, BP: 10.47 kW, FP: 22.19 kW, and m: 32.05%

2. Calculate the brake power output of a single cylinder four stroke petrol engine

which is running at a speed of 400 rpm. The load on the brake drum is 24 kg

and the spring balance reads 4 kg. The diameter of the brake drum is 600 mm

and the rope diameter is 30 mm.

Answers: BP: 2.58 kW

3.

A single cylinder 4 stroke engine runs at 1000 rpm and has a bore of 115 mm

and a stroke length of 140 mm. the brake load is 60 N at 600 mm radius and

the mechanical efficiency is 80%. Calculate the brake power and mean effective

pressure.

Answers: BP: 3.77 kW, IP: 4.71 kW, Pm: 4 bars

4. The average piston speed of a 4 stroke petrol engine having piston diameter of

150 mm is 3.5 m/sec. The mean effective pressure acting on the piston is

0.786 MPa. Determine the power developed inside the engine cylinder.

Answers: IP: 12.10 kW

5. A 4 stroke IC engine running at 450 rpm has a bore diameter 100 mm and

stroke length 120 mm. the details of the indicator diagram are as fallows.

i) Area of indicator diagram = 4 cm2

ii) Length of indicator diagram = 6.5 cm.

The spring value of the spring used is 10 bar/cm. calculate the indicatedpower of the IC engine.


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Answers: IP: 2.17 kW

6. Following are the data collected from 4 stroke single cylinder oil engine at full

load.i) Bore = 200 mm

ii) Stroke = 280 mm

iii) Speed = 300 mm

iv) Indicated mean effective pressure = 5.6 bars.

v) Torque on the brake drum = 250 Nm.

vi) Oil consumed = 4.2 kg/hour

vii) Calorific value of oil = 41000 KJ/Kg

Determine:i) Mechanical efficiency

ii) Indicated thermal efficiency, and

iii) Brake thermal efficiency.

Answers: BP: 7.85 kW, IP: 12.3 kW, m: 63.8%, ith: 25.7%, bth: 16.4%

7. A person conducted a test on a single cylinder two stroke petrol engine and

found that the mechanical and thermal efficiencies of the engine were 0.7 and

0.2 respectively. The engine with a mean effective pressure of 6 bars ran at

300 rpm, consuming fuel at rate of 2.2 kg/hour. Given that the calorific value

of fuel is 42500 KJ/kg and that the stroke to bore ratio of the engine cylinder is

1.2. Find the bore and stroke length of the engine in cm.

Answers: BP: 5.19 kW, IP: 7.42 kW, d: 13.8 cm & L: 16.58 cm

8.

A 4 cylinder 2 stroke petrol engine develops 30 kW at 2500 rpm. The meaneffective pressure on each piston is 8 bars and mechanical efficiency is 80%.

Calculate the diameter and stroke of each cylinder, stroke to bore ratio is 1.5.

Also calculate the fuel consumption if brake thermal efficiency is 28%. The

calorific value of fuel is 43900 kJ/Kg.

Answers: d: 62mm, L=93mm & mf: 8.78 Kg/hr or 2.44 x 10-3kg/s.

9. A single cylinder 4S IC engine has a swept volume of 6 liters and runs at a

rated speed of 300 rpm at full load, the torque developed was measured with a

belt dynamometer whose pulley diameter is 1m. The tension in the tight side

and slack side of the belt is 700 N and 300 N respectively. 4 kg of fuel wasconsumed in one hour. The indicated mean effective pressure is 6 bars and CV

of the fuel is 42000 kJ/kg. calculate the Brake Power, Indicated Power,

Mechanical efficiency, Indicated thermal efficiency, Brake Thermal efficiency

and Brake Specific Fuel Consumption.

Answers: BP: 6.28 kW, IP: 9 kW, m: 69.7%, ith: 19.3%, bth: 13.4%,

BSFC: 0.63kg/kW-hr


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10.During a trail on a 4 stroke petrol engine, the following results were obtained.

i) Indicated power : 26 kW

ii) Brake power : 22 kW

iii) Engine speed : 400 rpm

iv) Fuel/BP hour : 0.33 kg

v)

CV of petrol : 44300 kJ/kg

Determine the following parameters

a) Mechanical efficiency

b) Indicated thermal efficiency

c) Brake thermal efficiency

Answers: m: 84.6%, ith: 29.11%, bth: 24.63%.

11.A diesel engine develops 5kW. Its indicated thermal efficiency is 30% and

mechanical efficiency 75%. Estimate the fuel consumption of the engine in (a)

kg/hr, (b) liters/hr. find (a) ISFC, (b) BSFC. Take CV of fuel as 42000 kJ/kg

and specific gravity of fuel as 0.87

Answers: mf: 1.905 Kg/hr, 2.189 lts/hr, ISFC: 0.285 kg/kW-hr, and BSFC:

0.381 kg/kW-hr

12.A single cylinder 4 Stoke petrol engine has bore 200 mm, stroke 400 mm and

runs at 400 rpm. The indicated mean effective pressure is 7 bar and the fuel

consumption is 10 l/hr. taking CV of petrol 45000 kJ/kg and specific gravity of

petrol is 0.8, determine the indicated thermal efficiency.

Answers: ith: 29.11%.

13.Following observations are taken during a trail of 4 stroke diesel engine.

Cylinder diameter: 25 cm, stroke: 40 cm, speed 250 rpm, brake load 70 kg,

brake drum diameter: 2m, mean effective pressure: 6 bars, diesel oil

consumption: 0.1 m3/min, specific gravity of fuel: 0.78, CV of fuel: 43900

kJ/kg. Determine (i) IP, (ii) BP, (iii) FP, (iv) Mechanical efficiency, (v) brake

thermal efficiency and (vi) indicated thermal efficiency.

Answers: BP: 17.97 kW, IP: 24.5 kW, FP: 6.53 kW, m: 73.3%, ith: 42.9%,

bth: 31.4%.

14.The following observations were recorded during a test on a 4 stroke engine,

bore: 25 cm, stroke: 40 cm, crank speed 250 rpm, net load on brake drum: 700

N, diameter of brake drum: 2 m, indicated MEP: 6 bar, fuel consumption

0.0013 kg/sec, specific gravity of fuel: 0.78, CV of fuel: 43900 kJ/kg. determine

(a) BP, (b) IP, (c) FP, (d) Mechanical efficiency (e) indicated thermal efficiency (f)

brake thermal efficiency.


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Answers: BP: 18.32 kW, IP: 24.5 kW, FP: 6.18 kW, m: 74.7%, ith: 42.9%,

bth: 32.1%.

15.The following details of a 4 Stroke petrol engine. Diameter of brake drum: 60.o3

cm, full brake load on drum: 250 N, brake drum speed: 450 rpm, calorific value

of petrol: 40MJ/kg, brake thermal efficiency: 32%, mechanical efficiency: 80%specific gravity of petrol: 0.82. Determine (a) BP, (b) IP, (c) fuel consumption in

liters/sec, and (d) Indicated thermal efficiency.

Answers: BP: 3.53 kW, IP: 4.41 kW, mf: 3.363x10-3liters/s, ith: 40.0%.

16.A 4 stroke petrol engine delivers a power of 35 kW with a mechanical efficiency

of 80%. The fuel consumed by the engine is 0.4 kg per kW/hr of power

developed. Calculate the indicated power, friction power, brake thermal

efficiency and fuel consumption per hour. If the air-fuel ratio is 14:1, calculate

the air consumption per hour. The heating value of fuel is 43000 kJ/Kg

Answers: IP:43.75 kW, Fp: 8.75 kw, BTH=20.97%, ITH=26.21%, ma= 196

kg/hr

17.A large diesel engine runs on four-stroke cycle at 2000 rpm. The engine has a

displacement of 25 Liters and a brake mean effective pressure of 0.6 MN/m2. It

consumes 0.18 kg/s of fuel. (Calorific value = 42000 KJ/kg). determine the

brake and thermal efficiency.

Answers: BP 250 kW, BTH=33.06%

18.2-cylinder, 4-S gas engine has a bore of 380 mm and a stroke of 585 mm. At

240 rpm, torque developed is 5.16 KN-m. Calculate,

(a) BP

(b)BMEP

(c) Mean piston speed in m/s

Answers: BP = 129.68 kW, Pmb= 4.9 bar, mean piston speed = 4.68 m/s

19.A 4 cylinder, 4-stroke spark ignition engine develops a maximum brake torque

of 160 Nm 3000 rpm. Calculate the engine displacement, bore and strokethe

brake mean effective pressureat the maxim engine torque is 960 kPa. Assume

bore is equal to stroke.

Answers: d = 0.1386 m = L, Vs= 2.09 x 10-3m

20.Calculate the brake specific fuel consumption of a diesel engine having a brake

thermal efficiency of 28%. The calorific value of fuel is 42500 KJ/kg.

Answers: BSFC = 0.3025 kg/kW-hr


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21.An engine develops 50 kW of power while running at full load with a mechanical

efficiency of 80%. Calculate the friction power. What will be the mechanical

efficiency of the engine at half load, if the friction remains the same?

Answers: FP = 12.5 Kw, mech= 66.6 %

22.

A single cylinder 4-S diesel engine gave the following results while running at

full load.

(i) Area of indicator diagram - 300 mm2

(ii) Length of diagram - 40 mm

(iii) Spring constant - 1 bar/mm,

(iv) Speed of the engine - 400 rpm

(v) Load on the brake - 370 N

(vi) spring balance reading - 50 N

(vii) diameter of the brake drum - 1.2 m

(viii) fuel consumption - 2.8 kg/hr

(ix)

CV of the fuel - 41800 kJ/kg(x) Diameter of the cylinder - 160 mm

(xi) Stroke of the piston - 200 mm.

Determine the following (a) IMEP (b) BMEP (c) BP (d) BSFC (e) Brake thermaland indicated thermal efficiencies.

Answers: IMEP = 7.5 bar, BMEP = 6.03 bar, BSFC =0.348 kg/kW-hr,

BTH=24.7%, ITH=30.79%

23.A 6 cylinder, 4-S diesel engine develops 125 kW at 3000 rpm. Its brake specific

fuel consumption is found to be 200 g/kWh. Calculate the quantity of fuel in

cubic centimeter to be injected per cycle per cylinder. Take the specific gravity

of the fuel as 0.85.

Answers: volume of fuel injected per cycle per engine = 0.05447 cm3

24.A 6 cylinder, 4-S IC engine with a stroke volume of 1.75 liters, develops 26.3

kW of indicated power while running at 504 rpm. The MEP is found to be 6

bars. Calculate the average number of times each cylinder misfires in one

minute.

Answers: approximate number of misfires = 2

25.

A single cylinder two stroke IC engine has a piston diameter of 10.5 mm andstroke of 120 mm. the mean effective pressure is 6 bars. If the crank speed is

1500 rpm, calculate the indicated power of the engine.

Answers: IP = 15.58 kW

26.A gas engine working on a four stroke cycle has a cylinder of 250mm

diameter, length .of stroke 450mm and is running at 180 rpm. Its


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mechanical efficiency is 80%. When the mean effective pressure is 9.65 MPa.

Find: (a) Indicated power (b) Brake power (c) Friction power

Answers: IP = 21.53kW; BP = 17.22 kW

27. A two stroke diesel, engine has a piston diameter of 200mm and a stroke

length 300mm. The engine has a mean effective pressure of 3.6 bars and a

speed of 400 rpm. The effective diameter of brake drum is 1 meter and the load

on this is 81 kg. Determine the indicated power, brake power and mechanical

efficiency, brake power and mechanical efficiency of the engine.

Answers: IP = 22.62 kW, BP = 16.64 kW, mech= 73.5%

28.A single cylinder 4-stroke IC engine has a bore of 180 mm, stroke of 200 mm

and a rated speed of 300 rpm. Torque on the brake drum is 200 Nm and

mean effective pressure is 6 bar. It consumes 4 kg of fuel in one hour. The

calorific value of the fuel is 42000 kJ/kg. Determine a) brake power b) indicated

power c) brake thermal efficiency and d) mechanical efficiency

Answers: BP = 6.28 kW; IP = 7.6k3W, BTH = 13.45%, mech= 82.3%

Unit-3 Machine Tools and Automation

1. The process of removing the excess material from the work piece in the form of chips is called

A) Chipping B) Cutting C) Machining D) Filing

2.

Power driven machine to perform machining is

A) Machine tool B) Cutting tool C) Motor D) None

3. Generally the machine tools produce

A) Cylindrical surface only B) Flat surface onlyC) Either cylindrical or flat surface D) Neither cylindrical not flat surface

4. _____ is the mother of all machine tools

A) Drilling machine B) Lathe C) Milling machine D) Planning machine

5.

To cut the material properly, the tool should be _____ than the material of the work

A) Harder B) Softer C) Costlier D) Cheaper

6. In a lathe if the tool is moved perpendicular to the axis of rotation of the work. It produces a

A) Cylindrical surface B) Flat surface

C) Smooth surface D) Rough surface

7. _____ is not a part of center lathe


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A) Tail stock B) Lead screw C) Feed rod D) Arbor

8. The housing comprising of the feed gear box and cone pulley in a lathe is called

A) Head stock B) Tail stock C) Bed D) Carriage assembly

9.

In a lathe, carriage assembly consists ofA) Apron B) Tool post C) Saddle D) All of the above

10.A part of a lathe which is used for cutting threads accurately and designed for other operations is

A) Feed rod B) Lead screw C) Apron D) Gear box

11.A tailstock is the movable part of the lathe that carries the _____ in it

A) Wire center B) dead centerC) Both live and dead center D) None

12.The operation to produce a flat surface normal to the rotational axis of the spindle of the lathe is

called

A) Plain turning B) Facing C) Parting D) Grooving

13.The process of producing a conical surface from a cylindrical work piece is called

A) Taper turning B) Conical turning C) Plain turning D) Knurling

14.A taper may be turned on a lathe by

A) Form tool B) Swiveling the compound rest

C) Tailstock offset D) All of the above

15.To drill a hole on a lathe, a drill bit should be held in

A) Tool post B) Tailstock sleeve C) head stock D) Compound rest

16. In taper turning by swiveling the compound rest on a lathe, compound rest is swiveled to an angleequal to

A) taper angle B) taper angle C) taper angle D) one taper angle

17.The taper turning by offsetting the tail stock is best suited for

A) Short tapered lengths B) Small tapers on long jobsC) Both A and B D) None

18. If the larger diameter D=90 mm, smaller diameter d=80 mm and length l=100 mm, the amount of

taper or conicity is

A) 1 B) 0.1 C) 10 D) 0.01

19.The angle at which the compound rest will be swiveled when cutting a taper on a piece of work

having the larger diameter of 60 mm, smaller diameter 20 mm and length of tapered portion of 80mm is


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A) 12 4 B) 12 C) 14 2 D) 45

20. In thread cutting on a lathe, the saddle receives traversing motion through

A) Feed rod B) Lead screw C) Tail stock D) Head stock

21.

The most commonly used standard tapers areA) Morse taper B) Metric taperC) Brown and sharp taper D) All of the above

22.The method of machining operation in which the work piece is reduced to the cylindrical sectionis called

A) Knurling B) Grooving C) Tapping D) Turning

23.A metal cutting process is carried out by a rotating cutting tool to make circular holes in solidmaterials is called

A) Drilling B) Grooving C) Tapping D) Spot facing

24.The sensitive drilling machine is a small machine designed for drilling

A) Small holes at slow speed B) Small holes at high speedC) Large holes at slow speed D) Large holes at high speed

25.The sensitive drilling machine are capable of rotating drills of diameters from

A) 1 mm to 5mm B) 1.5 mm to 15.5 mmC) 10 mm to 20 mm D) 0.5mm to 1.5 mm

26.

The suitable drilling machine for drilling medium to large and heavy work piece is

A) Radial drilling machine B) Bench drilling machineC) Pillar drilling machine D)Upright drilling machine

27.Radial drilling machine has a capacity for drilling holes upto

A) 5 mm B) 10 mm C) 100 mm D) 50 mm

28.The operation of finishing a drilled holes by means of multi teeth cutter is called

A) Reaming B) Boring C) Tapping D) Knurling

29.Boring is the operation performed in drilling machine to

A) Enlarge a drilling hole B) Correct out of roundness of the hole

C) Correct the location of a hole D) all of the above

30.The operation of producing conical seating at the end of a hole is called

A) Counter boring B) reaming C) Counter sinking D) Boring

31.A cutting tool is used in boring operation in a drilling machine has

A) Only one cutting edge B) Two cutting edge


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C) Multiple cutting edge D) No cutting edge

32.The operation of enlarging the end of a hole cylindrically is called

A) Boring B) Counter boring C) Counter sinking D) Spot facing

33.

Counter bore is a tool used forA) Drilling B) Boring C) Counter boring D) Reaming

34.The cutting speed in counter boring compared to drilling speed is

A) 25 % more B) 50 % more C) 50 % less D) 25 % less

35.The operation of smoothening and squaring the surface around a hole for the seat for a nut iscalled

A) Spot facing B) Reaming C) Tapping D) Boring

36.

The process of cutting internal threads with a thread cutting tool is called

A) Reaming B) Tapping C) Counter sinking D) Counter boring

37.A tap is a fluted threaded tool used for cutting

A) External threads B) Gears C) Internal threads D) None

38.The size of the drilling machine is specified by the

A) Diameter of the column B) Length of the armC) Maximum drilling radius D) All of the above

39.

The operation performed on a drilling machine at the lowest speed is

A) Reaming B) Drilling C) Tapping D) Bornig

40.The spot face cutter is similar to

A) Tap B) reamer C) Counter sink D) Counter bore

41.______ is not a drilling operation

A) Taper turning B) Tapping C) Reaming D) Spot facing

42.Which of the following operation is first performed?

A) Tapping B) Drilling C) Boring D) Spot facing

01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20

C A C B A B D A D B B C A D B A B A A B

21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

C B D D A B B C D A D C A B C D A B C D


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41 42 43 44

C D A B

1. What is a machine tool?

2. What is a lathe?3. What is drilling ?

4. Sketch and explain the following drilling operations.

(i) Boring.(ii) Counter boring.

(iii) Counter sinking.(iv) Drilling.

(v) Reaming.(vi) Tapping.(vii) Spot facing.

5. Describe the following milling operations with suitable sketches.a. Plane or Slab milling

b. Slot millingc. End milling

6. Define the following;

(i) Cutting speed, (ii) Feed, (iii) Deapth of cut7. what are the machining operations that can be performed on an engine lathe ?

8. What is milling?9. Explain the follwing lathe operations with the help of a neat sketch

(i) Turning, (ii) Facing, (iii) Knurling, (iv) Thred cutting,(v) Drilling

10.What is a taper? Describe the following methods of taper turning with a neat sketch.

(i) Tailstock off-set method(ii) Compound rest swivelling method

Robotics and Automation

11.

What is Robotics?12.Classify the robots configuration? And explain with neat sketches.

13.List the applications of robotics.14.

Describe the advantages and disadvantages of robotics.

15.What is automation? List the types.16.Explain the types of automation with neat sketches.17.What is an NC and CNC machines?

18.Describe the basic elements with simple block diagrams of NC and CNC machines.19.

Describe the advantages and disadvantages of NC and CNC machines.

20.Give the advantages and disadvantages over NC and CNC machines.

Unit-4 Engineering materials and joining processes

Engineering Materials1. List the types of materials?2. What is a ferrous and non-ferrous material?3.

List the applications of ferrous and non-ferrous materials.

Composites1. Define the composites.2. List the types of composites and explain.


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3. List the applications of composites materials.

JOINING PROCESSWELDING, BRAZING & SOLDERING

1.

What is welding process ?2. What are the uses of welding?

3.

How are welding processes classified?4. Explain the principle of oxyacetylene weiding.

5. Explain the different flame charecteristics of oxyacetylene welding with neat diagrams.6.

Describe the principle of arc welding with suitable welding circuit diagram.7. What is an electrode? explain the various types of electrodes.

8. Describe the brazing process.9. Describe the soldering process.

10.Differentiate between soldering, brazing and welding.11.Why flux is used while joining two metal pieces? Name commonly used fluxes.12.Briefly discuss the three types of flames used in gas welding and mention their application.

Unit-5 Refrigeration, Air -Conditioning

1.

The cooling of or removal of heat from a system is known as

A) Air-conditioning B) Air cooling C) Refrigeration D) Scavenging

2. A machine which produces cold is called

A) Refrigerator B) Cooler C) Air-Conditioning D) Engine

3. The primary function of a refrigerator is to

A) Reduce the temperature of the system onlyB) Maintain the temperature of the system onlyC) Reduce the temperature and maintain itD) Reduce the temperature below the atmospheric temperature and maintain it

4. Refrigerator is used in

A) Ice making B) Processing food materialC) Industrial air-conditioning D) All of the above

5. The unit of refrigeration is expressed in

A) KN B) KW C) KJ D) KPa

6. One ton of refrigeration is equal to

A) 21 KJ/min B) 420 KJ/min C) 210 KJ/min D) 620 KJ/min

7. The performance of a refrigeration system is expressed by a term known as

A) Mechanical efficiency B) C O PC) Thermal efficiency D) Overall efficiency


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8. The principle of a refrigeration is based on

A) Law of conversation of energy B) First law of Thermodynamics

C) Second law of Thermodynamics D) Zeroth law of Thermodynamics

9. An example for a refrigerant is

A) Ammonia B) Methyl chloride C) Freon D) Any of these

10.The ratio of heat extracted from the refrigerator to the work done is called

A) Performance ratio B) Thermal efficiency C) C O P D) performance index

11.Fluids like Ammonia, Freon, Methyl chloride, carbon monoxide are commonly used ____

A) Refrigerants B) Fuels C) Lubricants D) Coolants

12.

A refrigerant is a medium which continuously ______

A) Extracts heat from the surroundings

B) Extracts heat from space within the refrigeratorC) Rejects heat from the space within the refrigeratorD) None

13.The most commonly used refrigerant in vapour absorption refrigeration system is

A) Freon B) CO2 C) SO2 D) NH3

14.

The refrigerants, Freon-12 and Freon-22 are most commonly employed in

A) Air-conditioners B) Ice plants

C) Marine refrigerators D) Industrial refrigerators

15.______ should not be the property of an ideal refrigerant

A) Low boiling point B) high freezing pointC) High latent heat D) High critical temperature

16.An ideal refrigerant should have

A) Low specific heat B) Low viscosityC) High thermal conductivity D) All of the above

17.Co-efficient of performance of a refrigerator is always

A) < 1 B) = 1 C) > 1 D) = 0

18.To accomplish the task of producing the cooling effect, a refrigerator must consists of

A) Evaporator B) Condenser C) Expansion device D) Evaporator

19.The heart of a refrigerator is

A) Condenser B) pump C) Condenser D) Evaporator

20. In a condenser, the refrigerant vapour gives off its

A) Sensible heat B) latent heat C) Super heat D) None


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21. If Q is the amount of heat absorbed or removed in kW and W work supplied in kW, then COP

of the refrigerator is given by

A) Q/W B) W/Q C) W x Q D) QW

22.

The purpose of liquid refrigerant through an expansion valve before to the evaporator is toA) Increase its pressure B) Decrease its pressure onlyC) Decreases it temperature and pressure D) None

23.The co-efficient of performance is always

A) Equal to efficiency B) Lass than efficiencyC) Reciprocal of the efficiency D) None

24.Relative COP is equal to

A) Actual COP x Theoretical COP B) Theoretical COP / Actual COPC) Actual COP - Theoretical C D) Actual COP / Theoretical COP

25. In a refrigerator, heat rejected is _____ heat absorbed

A) Equal to B) Less than C) Greater than D) None

26.

Dichlodifloro methane is popularly known as

A) Freon-12 B) Freon-22 C) Freon-32 D) Freon-42

27.The most commonly used refrigerant in vapour compression refrigeration system is

A) SO2 B) CO2 C) Freon-22 D) Freon-12

28.The vapour compression refrigeration system works solely on

A) Heat Energy B) Mechanical Energy C) Electrical Energy D) None

29.The vapour absorption refrigeration system works solely on

A) Heat Energy B) Mechanical Energy C) Electrical Energy D) None

30. In a refrigerator, heat is rejected by the refrigerant in a

A) Compressor B) Evaporator C) Condenser D) Expansion valve

31.

In a refrigerator, heat is absorbed by the refrigerant in a

A) Compressor B) Evaporator C) Condenser D) Expansion valve

32.The difference between vapour compression and vapour absorption refrigeration cycle is that

A)

Absorption cycle requires more work input

B) Absorption cycle requires less work inputC) Vapour compression cycle requires a pumpD)None of the above


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33. In a vapour compression cycle, the refrigerant is in the form of superheated vapour before passing

through

A) Expansion valve B) Condenser C) Evaporator D) Compressor

34.A domestic refrigerator has a C O P

A) = 1 B) < 1 C) > 1 D) Any value

35.

In vapour compression refrigeration cycle, the lowest temperature occurs in

A) Compressor B) Condenser C) Expansion valve D) Evaporator

36.The capacity of a refrigerator is one tonne. This means that the heat removing capacity of the

refrigerator is

A) 1000Kcal/hr B) 2000Kcal/hr C) 3000Kcal/hr D) 4000Kcal/hr

37.

The refrigerating effect means

A) The heat rejected from the system/hrB) Work done on the systemC) Heat absorbed in the cycle from the body or space to be cooled

D) None of the above

38.A refrigerant, which has the lowest boiling point is

A) Freon-12 B) Freon-22 C) CO2 D) NH3

39.The C O P of the vapour absorption cycle as compared to vapour compression cycle is

A) Higher B) Lower C) Same D) None

40.

The refrigerant system used for refrigeration in aero plane is

A) Carbon dioxide B) Ammonia C) Freon-12 D) Air

41.The refrigerating system used for most of domestic refrigerators is of the type of

A) Vapour absorption B) Vapour compression

C) Air refrigeration D) None

42.For large commercial installations, ammonia is used as refrigerant because

A) Its has low specific volume B) It is non-toxic

C) It is colorless and odorless D) All of the above

43.Freon-12 is the refrigerant mostly employed in domestic refrigerators because it

A) Is non-toxic B) Is colorless and odorlessC) Has low specific volume D) All of the above

44.Freon-12 as compared to ammonia having

A) Less cost B) High cost C) Same cost D) None


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45.The liquid and vapour refrigerants should have _____ viscosity

A) Low B) High C) Normal D) None

46.Vapour compression refrigerator is also called

A) Sensible heat pump B) Latent heat pumpC) Super heat pump D) None

47.The air conditioning means the control of

A) Temperature B) Humidity C) Air motion D) All of the above

48.The main component of room air conditioner is

A) Piston B) Condenser C) Bed D) Arbor

49.Refrigeration cycle of an ideal refrigerator works on

A) Carnot cycle B) reversed Carnot cycle C) Otto cycle D) Diesel cycle

50.The chemical name of Freon-12 refrigerant is

A) Dichloro Methane B) Dichloro diflouro MethaneC) Dichloro Ethane D) Diflouro Ethane

01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20

C A D D B C B C D C A B D A B D C D D B

21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

A C C D C A D B A B B B D C D C C C B D

41 42 43 44 45 46 47 48 49 50

A D D B A B D B B B

1.

Define refrigeration effect, refrigeration capacity and coefficient of performanceof a refrigeration

system.2. What is the commonly used unit for capacity of a refrigeration system. Explain how its value is

calculated in SI units .List the areas where refrigeration is used.3. Draw a schematic diagram of vapour compression refrigeration system and explain its working.4.

Draw a schematic diagram of vapour absorption refrigeration system and explain its working.5. Define a refrigerant.

6. What are the basic requirements of a good refrigerant?

7. Name the commonly used refrigerants & its uses.

8. Defne the term air - conditioning.


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9. Explain the working of room air conditioner with a neat sketch & its application.10.What is the difference between refrigeration and air conditioning? Explain.

11.Explain in brief properties of good refrigerant.12.

Distinguish between the vapour compression and vapour absorption refrigeration.

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