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WWW.VIDYARTHIPLUS.COM

WWW.VIDYARTHIPLUS.COM V+ TEAM

RAJALAKSHMI ENGINEERING COLLEGE

DEPARTMENT OF MECHANICAL ENGINEEIRNG

GE 6251BASIC CIVIL AND MECHANICAL ENGINEERING

II SEMESTER

QUESTION BANK

Part-A

UNITI

1. Define Surveying.

It is defined as the processofmeasuring horizontal distances,

verticaldistancesand included

angles to determine the locationofpoints on, above or below the earth

surfaces.

The term surveying is the representation ofsurface features in a

horizontal plane.

The proces ofdetermining the relative heights in the vertical plane is

refered as leveling.

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2. What is meant byObjectives of Surveying?

The data obtained bysurveying are used to prepare the plan or mapshowing the ground

features.

When the area surveyed is smal and the scale to whichits result

ploted is large, then it is

known as Plan

When the area surveyed is large and the scale to which its result

ploted is smal, then it is caled

as a Map

Seting out of any engineering work like buildings, roads, railway

tracks, bridges and dams

involves surveying

3. Define Plane Surveying

The surveying where the efect ofcurvature of earth isneglected and

earthssurface is treated as

plane, is caled surveying.

The degree ofaccuracyin this type of surveying is comparatively low.

Generaly when the surveying is conducted over the area less than260

Sq.Km., they are treated

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as plane surveying.

Plane surveying isconducted for the purpose ofengineering projects.

4. Define Geodetic Surveying

The efect ofcurvature istaken into account.

It is also known as Trigonometrical Surveying.

It is a special branch of surveying inwhich measurementsare taken

with highprecision

instruments.

Calculations are also made with help ofspherical trigonometry.

It is generalyadopted bythe Great TrigonometricalSurvey Department

of India.

5. Mention the Classificationof surveying:

Chain Surveying

Compas Surveying

Theodolite surveying

Plane Surveying

Techeometric Surveying

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6. What are the primarytypes of surveying?

1. Plane surveying

2. Geodetic surveying

7. Stateanytwo types of cement and concrete.

Typesofcement

1. OrdinaryPortland cement

2. Rapid hardening cement

Typesofconcrete

1. Plain cement concrete

2. Reinforced cement concrete

9. Mention the Advantages and disadvantages of chain surveying?

Advantages:

It is simple

It does not require anycostly equipment

It is adopted for preparing plans for smal area

Disadvantages

It cannot be used for large areas

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It cannot be used in thick bushy areas with upsand downs.

Chain surveying is not always accurate.

10. Define Magnetic Bearing:

1. It isthe angle between the magnetic meridian and the line.

2. The angle is always measured inthe clockwise direction

3. It isthe direction shown byafreelysuspended magnetic needle

4. The magnetic meridianis also caled bearing.

11. Define Whole Circle Bearing:

The bearing of lines measured from the North is caled Whole Circle

Bearing.

The angle is reckoned in the clockwise direction from 0o coinciding

with the north.

12. Define Fore Bearing and Back bearing:

Every line has two bearing namely fore bearing and back back bearing

Fore bearing is the bearing taken in the directionofsurveying and Back

bearing is the bearing

takenin the reverse direction.

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13. Distinguishbetween the fore bearing and the back bearing should

be 180o.

It meansthat one or bothstations of the line are subjected to local

atraction.

Thus, local atraction is the influence caused on the measured

bearings of lines due to the

presence ofmaterials like railway track, curent carying wires or cables,

etc.,

14. Define Leveling:

It is a surveying method used to determinethe levelofpoints/objects

with reference to the

selected datum.

It is also used to set out engineering works.

15. Define Back Sight.

It is the reading taken on the staf held at a point, the elevation of which

is known already. It is

usefulto know the new height of the instrument.

16. Define Foresight. .

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It is the reading taken on the staf held at a point of unknown elevation.

From, F.S., the height of

the line of instrument above the point can be obtained. It is useful to

find the elevation of the

point.

17.Write the arithmetic equation used inrise and fal method of

leveling.

S B.S - SF.S =SRise - S Fal = Last R.LFirst R.L.

18. What are the constituent materials of bricks?

1.Alumina 2. Silica 3. Lime 4. Oxide of Lime 5.

Magnesia

19. What are the uses of stones inbuilding construction?

i) Stonesare used to cover floor of buildings ofvarious types suchas

residential, commercial,

industrialetc.

i) Stones are also used as balast for railway track

i) Stones are used as flux in blast furnace.

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20. Mention some important building stones in India?

i) Granite i) Sand stonei) Lime stone iv) Laterite v) Gnisses vi)Marble

21.What are the four distinct operations of brick manufacturing?

i) Preparation of brick earthi) Moulding ofbricks i) Drying of bricks iv)

Burning of bricks

22.How are bricksclassified?

Bricks are clasified on the basis of method of manufacturing as

i) Unburnt or sundried bricks

i) Burnt bricks

a) First class bricks

b) Second class bricks

c) Third classbricks

d) Fourth classbricks

23.Listout the uses of bricks.

i) Bricks are mainly used for the construction ofwals in residential and

industrial structures

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i) Bricks when moulded in the shape ofguter can be used as drains.

i) Sandlime bricks are used for ornamentalworks.

24.State the characteristics ofgood bricks.

i) Bricks should haveuniform copper colour.

i) Bricks should not absorb water more than20% byweight when

immersed in water for 24

hours.

i) Bricks should have even surface with sharp and square edges.

25.What is frog in bricks?

A Frog is a mark of about 10 mm to 20 mmwhich is placed on the raw

brick during moulding.

This serves two purposes asi) Indicates the trade name ofthe

manufacturer. i) It afords a key

for mortar when the next brick is placed over it.

26.What are the raw materials used for the manufacturing of cement?

Lime (CaO) - 62%

Silica (SiO2) - 22%

Alumina - 5%

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Calcium Sulphate 4%

IronOxide- 3%

Magnesia - 2%

Sulphar - 1%

Alkalies - 1%

27.List the uses ofcement.

i) Cement is used for preparationoffoundations, foot pathsetc.

i) Cement is used for manufacture of precast pipes, piles, fencing posts

etc.

i) Cement mortar is used for masonrywork, plastering, pointing etc.

28. Statethe various types ofcement.

i) Quick seting cement i) Low heat cement i) High alumina cement iv)

Acid resistant cement

29. Statethe various properties of good cement.

i) The colour of cement should be uniform

i) Cement should be free fromlumps

i) Ifa smalquantity of cement is thrownin to abucket ofwater , it should

sink

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30. Statethe various types ofsteel.

i) Mild steel or Low carbon steelcarbon content from 0.10 to0.25percent i) Medium hard

steelor medium carbon steelCarbon content 0.25 to 0.6 percent i)

Hard steel or Highcarbon

steelCarbon content from 0.60 to 1.5 percent

31. List down the commercial forms of steel sections used in the

construction.

i) Round bars i) Square barsi) Torsteel iv) Plates v) Flat bars vi) Angle

sections vi) Channelsections vi) I-sections

UNITII

1. Define Objectives of foundation:

To distribute the total load coming onthe structureon a larger area

To support thestructures

To give enough stability to the structureagainst various disturbingforces, such as wind and rain.

2. What is meant byDeep foundation?

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Deep foundation consists ofpile and pier foundation.Pier foundations

are rarely used for

buildings.This consists incarying downthrough the soila huge

masonrycylinder whichmay be

supported on solid rock.

3. Which typesofFailures occur in foundation?

1. Unequal setlement ofsoil

2. Unequal setlement ofmasonry

3. Withdrawal of moisture from sub soil.

4. Define Superstructure.

Superstructuremainlyconsists ofwals, doors windows and lintels.

The purpose of superstructure is to provide the necessary utilityofthe

building, structuralsafety,

fire safety, sanitation and ventilation.

5. Define EnglishBond:

English bond consists of headers and Stretchers in alternative courses

of elevation.

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A queen closer is placed next to the quoinheader in each header course

to the fulthickness of

wal. Each alternative header lies centraly over a stretcher of the

stretcher course.

6. What are the diferent types ofdam?

1. Rigid Dams

? Solid gravity dam

? Arch Dam

? Butres dam

? Timber and steeldam

2. Nonrigid dams.

? Earth Dams

? Rockfils dams.

7. What are the diferent types ofbridges?

? Permanent bridges

? Back bridges

? Through bridges

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? Semi throughbridges

? Straight bridges

? Skew bridge

? Arch Bridge

? SlabBridge

? Tbeam and slab bridge

? Bow string andgirder bridge

? SteelArch bridge

8. What is cement concrete.

Concrete is defined as a building material obtained bymixing cement,

fine and course aggregates

and water in suitable proportions. The resultant plasticmixture after

curing becomes hard mas.

The course aggregates are broken stone, broken bricks or gravel.

Thefine aggregate is sand or

surkiand the binding material is lime or cement

9. List out the properties of cement concrete.

i) It is plastic when freshlyprepared and can be moulded to anyshape.

i) Concrete does not lose its strength with age and does not require

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maintenance. i) It is durable and not afected by weather.

10.State the various uses of cement concrete.

i) Concrete is mainly used in the construction offoundations, columns,

floors, roofslabs, beams, lintels, water tanks, sumps etc

i) Concrete is used inmassive structures such as dams and bridges.

i) Concrete is used in the construction ofbunkers, silos etc.

11. List out the few types of specialCement concrete.

i) No- fines concretei) Pre-cast concrete i) Fibre reinforced concrete

iv) Prestreses concrete

12.What is meant bywater cement ratio?

The rationof weight of water used to that of cement istermed as water

cement ratio. Water

cement ratio depends upon the strengthand workability desired and

method of compaction.

13. Whyare steelrods used in Reinforced Cement Concrete?

Concrete isgood incompression and weak in tension. To take althe

tension forces steel rods

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are used in concrete.

14. Define curing ofconcrete.

The finished concrete surface should be kept wet for at least 7 days to

promote continued

hydration ofcement. This is caled curing ofconcrete.

15. What is meant by1:2:4 concrete mixes?

In 1:2:4 concrete mix, the materials are measured by the mass like 1

part of cement, 2 partsof

fine aggregate 9 sand and 4 partsof courseaggregate.

16. How to select the site for foundation?

i) Soil at the building site should not be ofartificialy made- up type.

i) Site should not be undulating since this leads to increase in cost for

leveling the ground.

i) The site should have its general slope and the ground water table in

the site should not be

high.

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17.Define Bearing capacity, Ultimate bearing capacityand Safe bearing

capacity?

Bearing capacity: It is defined asthe maximum load per unit area which

the soil wil resist safely

without displacement.

Ultimate bearing capacity: It isthe gross pressure intensity at the base

of the foundation at which

the soil fails in shear.

Safe bearing capacity: It isthemaximum presure which the soilcan

carysafely without risk of

shear failure.

18.How to improve thebearing capacity ofsoil?

i) Byincreasing depth offoundationi) By cement grating

i) By draining the subsoilwater iv) Bycompacting the soil

19. What are the loads acting on foundation?

i) Live load i) Dead load i) Wind load

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20. List out the requirements ofa good foundation?

The foundation should be so located that it is able to resist any

unexpected future influence

whichmay adversely afect its performance

21. Mention thetypes of foundation?

Foundations are classified in to two types depends on the depth as

i) Shalow foundation

i) Deep foundation

Shalow foundations are those in which the depth is equal to or les than

its width. When the

depth is more than the width, it is termed as a deep foundation

22. Mention thediferent types of shalow foundation?

i) Isolated column footing i) Wal footing i) Combined footing iv)

Cantilever footing v)

Continuous footing vi) Inverted arch footing vi) Stepped footing

23.Mention the diferent types of deep foundation?

i) Pile foundation i) Pier foundation i) Wel foundation

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24.What are the causes of failure of foundation?

i) Unequal setlement ofthe sub-soil

i) Shrinkage ofthe sub-soil due to the variations in the depthofwatertable

i) Sudden earthquake and heavy rains

25.What are the remedialmeasures for the failure of foundation?

i) Foundation should be takendown to a depth where no ground watermovement occurs.

i) The soil moisture content is maintained constant.

i) The sides of the foundation should be protected by proper drainage.

UNIT III

POWER PLANTS, PUMPS AND TURBINES

1. What are the clasifications ofpower plants based on non-renewable

source of energy?

o Steampower plant.

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o Nuclear power plant.

o Diesel power plant.

o Gas turbine power plant.

2. What are the clasifications ofpower plants based on renewable

source of energy?

o Hydro-electric power plant.

o Solar power plant.

o Wind power plant.

o Tidalpower plant.

3. Write the steam power plant circuits.

o Coal and ash

o Air and flue gas

o Feed water and steam.

o Cooling water circuit.

4. What is the functionof economiser?

The economiser is used to pre-heat the feed water.

5. What is the functionof super heater?

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The function of super heater is used to super heat the saturated steam

and to

supplythe steam to turbine.

6. What are the advantages of thermalpower plants?

o Power can begenerated continuously.

o Power plant can withstand the varying load.

o Initial cost low

o The construction period for the power plant is minimum.

7. What are the dis-advantagesof thermalpower plants?

o Power generation cost is high.

o Handling ofcoal is a major problem.

o Handling ofcoal is a major problem.

o Life of the plant is low.

o Plant eficiencyis less.

8. What is the functionof penstock?

Penstock is the pipe made up of steelor concrete used to carywater

from the

dam to power house.

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9. What is meant by trash rack?

Trash rack is provided to prevent the debris fromgeting entry to power

house.

This consists ofnumber ofsteel bars and it is placed acrossthe intake to

prevent debris.

10. What is meant bydraft tube?

Draft tube isan integralpart of reaction turbine. Draft tube connects the

runner

exit to tail race. The area of the draft tube is same as that ofthe runner

to avoid shock

and is circular cros section. The water after doing work on the turbine

runner passes

through the draft tube.

11. Write the advantages ofhydro electric power

plant. o This plant useswater for power

generation. o Water is easily available.

o Beside power generation, thisalso provides benefits like irigation,

flood control,

afore

station-culture.

o Fuelcost iseliminated.

o Plants are automated and hence operating labor cost is low.

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12. Write the dis-advantages of hydro electric power plant.

o The plant disrupts the surounding aquatic ecosystems.

o Initial cost of plant is veryhigh.

o Failure ofdams is potentialy serious.

o Large investments, long gestationperiods are major issues.

13. Drawthe layout ofdiesel power plant.

Fuelstorage Oil cooler

Generator

Feed Diesel

pump engine

I/P air

Water pump

Air

compressor Layout of diesel power plant

14. What arethe advantages of dieselpower plants?

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o Power plant can be easily instaled.

o The plant is smaler in size and fuel handling and storage is easier.

o Quick starting and easy pickup is possible.

o No ash disposalproblem.

15. What arethe dis-advantages of dieselpower plants?

o Fuel ismore expensive.

o Repair and maintenancecost is high.

o Capacity of diesel engineis low.

o Livesof plants are low.

16. What is the function of re-generator?

The heat obtained inthe exhaust gases of LPT is utilized in the re-

generator for

transfering heat to the cold air coming out of HPC.

17. What is the function of intercooler?

This reduces the work ofcompressor; hence the power spent by

compressor is les when the air is

cooled.

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18. Write the advantagesofgas turbine power plants.

o The capital cost of plant is low.

o This can be quickly commissioned.

o It requires les space.

o Capacity to use wide variety of fuels.

19. Write the advantagesofgas turbine power plants

o About two third of the power developed by the turbine isused to

drive the compressor.

Hence net output ofplant is low.

o Low efiency.

o Needs special cooling arangements.

o Operating temperature is highof the orderof20000C.

20. Define nuclear fission.

Nuclear fission is defined as the spliting up the nucleus of an atom into

parts where enormous

amount ofenergy is released and this energy is used to generate power.

21. Write the function of moderator

In the chain reaction, the neutrons produced are fast moving neutrons.

They are lessefective

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incausing fission ofU235 and tryto escape from the reactor. To improve

the utilization of these fast

neutrons, their speed is reduced in this moderator.

22. What is the function of control rods?

The energyproduced in the reactor during chainreactionis enormous.

Ifthis is not controled

properly entirecore and structure may melt and radioactive rays may

come out of the reactor. The control

rods do this control.

23. Explain about Biological shielding ofnuclear reactor.

During fission reaction alpha particles, beta particles, gamma rays and

neutrons are produced.

Theseradioactive rays are harmful to operating men. To protect from

such harmful efects, thick

concreteshielding is provided al round the reactor.

24. What arethe advantages of nuclear power plant?

o Requires less space compared to steampower plant.

o Fuel required is negligible compared to coalrequirement in

steampower plant.

o Fuel transport cost is less.

o Cost ofErection is less.

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o Water required is veryless.

25. What arethe dis-advantages of nuclear power plant?

o Initial cost ishigher.

o Not suitable for varying load condition.

o Maintenance cost is higher.

o Trained workers / Engineers are required to handle the operation.

26. What is pump?

Pump is a mechanicaldevice which is used for moving liquids or gases

from lower pressure

to higher pressure. In a pump mechanical forces are used to move the

fluids.

27. Write the clasification ofpump with examples.

o Rotodynamic eg; Centrifugal pump.

o Positivedisplacement pump eg: Reciprocating pump

28. What is meant bycentrifugalpump?

Centrifugal pump isrotodynamic pump which uses the mechanical

energy ofthe rotating impeler

to increase the velocity of a fluid by the applicationof centrifugal force.

The fluid enters the pump

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impeler along the rotating axis and gets accerelated.flows

radialyoutwards into a casing and exits

throughthe piping system. It isgeneralyused for large discharge

throughsmaler heads.

29. What is meant byreciprocating pump?

A reciprocating pump isa positive displacement pump in which liquid is

sucked and then it is

pushed or displaced due to the thrust exerted onit by a moving

member which results in lifting height.

The pump has oneor more chamber which are alternatelyfited with

liquid to be pumped and then

emptied again. Thus reciprocating action is being continued within the

pump and hence, the pump is

caled reciprocating pump.

30. What arethe types of reciprocating pump?

o Single acting reciprocating pump

o Double acting reciprocating pump

31. What is priming?

Priming is the operation of filing up ofwater in the suction pipe, casing

and a portionofdelivery

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valve to remove the air present inside. If any air is present, the pressure

developed acrossthe impeler

wilnot be suficient to suck the water from the sump. The deliveryvalve

is kept closed during priming.

32. What arethe types of casing?

o Volute casing.

o Vortexcasing.

o Difuser casing.

33. Defined turbine.

A turbine is defined as a hydraulic machine which converts hydraulic

energy into

mechanical energy and this mechanical energyis used to use to run an

electricalgenerator which is

directly coupled to the shaft of the turbine. Thus, mechanical energy is

converted into electrical energy.

A simple turbine wil have one moving part and a rotor assembly. The

rotating system is caled a runner

in a turbine.

34. What is meant byimpulse turbine withexample?

In this energyis available isonly kinetic energy, then the turbine is

known as impulse turbine.

Eg: Pelton wheelturbine.

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35. What is meant byreactionturbine with example?

In this the energyavailable is kinetic energy and pressure energy, thenthe turbine isknown as

reaction turbine. When the fluid through the runner, it is under

presureand the pressure energy goes

on changing into kinetic energy. Eg: Francis turbine

36. Write the function of casing.

o To prevent splashing ofwater.

o To lead the water to the tailrace.

o To act as asafeguard against any accidents.

UNIT-IV

INTERNAL COMBUSTION ENGINES

1. What is meant byI.C. engine?

In this type ofengine, combustion offuel takes place within the cylinder.

This type of engine includes

gas engine, petrolengines and diesel engines. These are generalyused

for road vehicles,

locomotives, and aircraft and for other industrial applications.

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2. Write the classification of I.C. engines.

Based on ignition:

o Spark ignition

o Compressionignition.

Based on fuel:

o Petrol engine

o Diesel engine.

Based on cooling system:

o Air cooled

o Water cooled.

3. What are the basic components of I.C. engines?

? Cylinder block.

? Cylinder head.

? Cylinder liners.

? Crankcase.

? Piston.

4. What is meant byTop dead centre?

This refers to theposition of the crankshaft whenthe piston is in its top

most position i.e., the

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position closest to the cylinder head.

5. What is meant byBotom dead centre?

This refers to the positionof the crankshaft when the piston is in itslowest positioni.e., the

position closest to the cylinder head.

6. Define stroke.

Strokeis defined as the distancetraveled by the piston while movingfromT.D.C to the

B.D.C.

7. What is meant byclearance volume?

The volume ofcylinder above the piston whenit is in the T.D.C.positionisrefered to as

Clearance volume (Vc).

8. What is compresion ratio?

This indicates the extent to which the charge in the engine iscompressed. This is

calculated as the ratio ofthe volume above the piston at B.D.C to the

volume above the piston at T.D.C. If

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V is the compression ratio

VS + VC

V = ---

VC

9. What is mean efective pressure?

This Is the average pressure throughout the whole power stroke. The

cylinder presure varies

considerablyduring power stroke. Thus it is more helpful to refer to themean pressure instead.

10. Define Engine torque.

It is defined as the force ofrotation acting about the crankshaft axis at

given instant of

time.

T = Fr

15. Define Carburetor.

The carburetoris a device for atomizing and vaporizing the fuel and

mixing it with the air in

varying proportions to suit the changing conditions of spark ignition

engines. Theair fuel mixture so

obtained fromthe carburetor is caled the combustible mixture.

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16. What arethe main functions ofa carburetor?

o It preserves fuelat a constant head.

o It vaporizes and atomizes the fuel and mixes it with the air.Vaporization means the

change of fuel from a liquid to a vapour whereas atomization is the

breaking up offuel

by mechanical system, so that everysmalparticle ofthe fuel is

surounded by air.

o It provides and controls the amount and strength of air-fuel mixture

under varying

conditions of load and speed ofthe engine.

o It provides easystarting with the engine in cold

o It ensures the engine to run slowlywithout missing and without

undue wastage of fuel,

o It provides maximum acceleration without hesitationto pick up speed

when the throtle

is suddenly or slowly opened.

17. Write the basic components inthe carburetor.

o

Venturi

o

Throtlevalve

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o

Choke valve

o

Fuel jet.

18. What arethe functions of Fuel injection pump?

In diesel engine, the fuel consists ofa cylindrical barrelhaving two ports

caled supply port and

spil port.Aspring loaded deliveryvalve is provided at the top ofthe

barelfor fueldelivery.

19. What arethe functions of Fuel injector?

The purposes ofthe fuelinjector is to injector a smal volume of fuel in afine spray and, to assists

in bringing each droplet into contact with a suficient oxygen to give

quick and complete

combustion.

20. Write the types ofIgnition system.

o

Bateryignition system(or coil ignitionsystem)

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o Magneto ignitionsystem.

21. Define spark plug.

Spark plug is defined as a device which is used to ignite the compresed

air-fuel mixture by

producing anelectric spark. It is usualy mounted onthe cylinder head.

22. What is the function of Boiler?

The function of the boiler is to evaporate water into steam at a presure

higher than the

atmospheric presure. Water free from impurities such as dissolved

salts, gases and non soluble solids

should be supplied to boilers. This isdone by suitable water treatment.

Steam isuseful for running steam

turbines in electricalpower stations.

23. Write the clasification ofboilers.

o Fire tube boilers.

o Water tube boilers.

24. Write the two diferences between Fire tube and water tube boiler.

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S.No Fire tube boiler water tube boiler

Hot gases pas through the tubes, Water passthrough the tubes,

1 water surounds them hot

Used for low pressure ga

Usese sdsfuror ounmeddsi thumemto high

2 steam(say pressure

3 Thermal efic 10ienbcary)l ow st

Teahemr maleficiency high

25. What arethe advantages of steamboiler?

o

Cost ofproduction is cheap when compared with other boilers.

o

Less space is required.

o

Fuel used is cheaper.

o

Steamengines can work under overload of25percent continuously.

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26. What arethe dis-advantages of steamboiler?

o

Water requirement is more.

o

Required more time for instalation.

o

Maintenance and operating costs are high.

? Coal handling is dificult.

UNIT-V

REFRIGERATION AND AIR CONDITIONING SYSTEM

1. What is Refrigeration?

Refrigeration is the proces of removing heat from anenclosed space or

from a

substance, under controled conditionsand moving the heat to

anunobjectional place.

2. What is meant byrefrigerator?

Arefrigerator is a machine that removes heat froma low temperature

region. Since energy

cannot be destroyed, the heat taken inat a low temperature must be

dissipated to the suroundings.

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3. State the second law of Thermodynamics.

Second law of Thermodynamics states that heat wil not pas from coldregionto a warm one

without the aid of an external agent. Therefore, arefrigerator wil

require this external agent or energy

input, for its operation.

4. What is meant byrefrigerant? Give some examples.

The substance which absorbs heat the materials placed in

refrigerator is caled

refrigerant.

E.g.: Freon-12, Freon-22, and Ammonia.

5. Define Ton of refrigeration.

The capacity if air conditioner and ice plant is represented in Tons.

1ton = 3024 kilo calories/hr

6. What is meant bysensible heat/

The amount of heat removed from the body or givento the bodyto

decrease or increase its

temperature is caled sensible heat.

7. Write the diferent kinds ofheat transfer modes with examples.

o Conduction E.g.: Metaland other solids

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o Convection E.g.:Heat through fluid

o Radiation E.g.: Sun light

8. Define Co-eficient of performance.

The purpose of the refrigerator is to remove heat fromthe cold region

while requiring as litle

external work as possible.

COP = Heat exerted / Work supplied

9. What are the applications of refrigeration?

o Preserving foodstufs in homes, restaurants and in large warehouses.

o

Used to liquefy gases like oxygen, Nitrogen, Propane and Methane. o

Preserving dairy products, fruits and vegetables.

o Preserving Meats, poultry and fish.

10. What arethe types of refrigeration system?

o Vapour compression refrigerationsystem

o Vapour absorption refrigerationsystem

11. Write the diference between Vapour compression and Vapour

absorption refrigeration system.

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S.No Vapourcompression system Vapour absorption system

The capacityofthe system is above Maximumcapacity is limited to

1 1000 tons 1000 tons

2 The operation is quit The operation is noisy

3 Maintenance cost is low Maintenance cost ishigh

12. Write the clasification ofrefrigerants with examples.

o Primaryrefrigerants E.g. R12, Ammonia, Freon.

o Secondary refrigerants E.g. Co2, CaCl2, NaCl

13. What is meant byAir conditioning?

Air conditioning is the process of controling the temperature and

humidity of air by heating or

cooling, humidifying or dehumidifying, and filtering the atmospheric air,

and thuscreating a healthy

and comfortable conditionfor human beings.

14. What arethe applications of Air conditioning?

o Providing relatively constant indoor environment for a building as per

humancomfort.

o For taler buildingswhere natural ventilationisnot possible due to high

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o In hospitaloperation theatres, to reduce infection risk.

15. Define Psychometry

It is the science whichdeals with the study of the behavior of air andwater vapour mixture.

16. Define dry bulb temperature.

It is the temperatureofair measured byan ordinary thermometer.

17. Define Wet bulb temperature.

It is the temperature ofair measured by thermometer when its bulb iscovered witha wet cloth and

is exposed to atmospheric air.

18. Define dew point temperature.

It is the temperature at which the moisture present in the air

begins to condense. It

coresponds to the saturationtemperature ofwater vapour in the

mixture ofair and water vapour.

19. Write the types ofAir conditioner?

o Window air conditioner

o Package air conditioner

o Centralised air conditioner

o Split type air conditioner

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20. Define relative humidity

It is defined as the ratio ofwater vapour present in thegivenamountofair to the mass ofwater

vapour present in the same volume under same temperature

conditions.

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