TRADE FITTER

2nd Semester Multiple Choice Questions

Exercise-01 Lathe Construction

1. Which one of the following is not a part of the centre lathe?

(a) Saddle (b) Feed rod

(c) Arbor (d) Lead screw

2. The headstock of a lathe is situated at the

(a) Right-hand end of the lathe bed (b) Left-hand end of the lathe bed

(c) Middle of the lathe bed (d) Bottom of the lathe bed

3. The horizontal feed, cross feed and screw cutting movement in a lathe is

controlled by

(a) Headstock (b)Tailstock

(c) Cross-slide (d) Apron

4. A face plate is held at

(a) Headstock spindle (b) Tailstock

(c) Tool post (d) Bed

5. Tumbler gear quadrant is used for

(a) Increasing the speed of the spindle

(b) Decreasing the speed of the spindle

(c) Changing the direction of rotation of the lead screw

(d) Changing the direction of the spindle

6. In a gap bed lathe, the gap is provided

(a) Just below the nose of the headstock spindle

(b) Just below the spindle of the tailstock

(c) In the middle of the bed(d) Anywhere in the bed

7. While drilling in lathe, the drill is held in the

(a) Headstock (b) Tailstock

(c) Compound rest (d) Bed

8. Back-gear mechanism is provided in cone pulley headstock to

(a) Reduce the speed of spindle

(b) Increase the speed of spindle

(c) Reverse the speed of spindle

(d) Transmit power from spindle gear to stud gear

9. Lathe bed is made of

(a) Mild steel (b) Cast iron

(c) High carbon steel (d) High alloy steel

10. To prevent lathe bed guideways from damaging by chuck while mounting

(a) Take the help of the supervisor

(b) Support it with screw jack

(c) Lift it with hand crane

(d) Place a wooden piece on the guideways

11. The sliding surfaces of the lathe bed are

(a) Flame hardened (b) Case hardened

(c) Normalised (d) Tempered

12. Which one of the following on a lathe is used to give depth of cut?

(a) Compound slide (b) Top slide

(c) By adjusting the tool (d) Cross slide

13. A tumbler gear unit consists of

(a) One gear (b) Two gears

(c) Three gears (d) Four gears

14. The lathe bed has

(a) One set of 'V guideways and flatways

(b) Two sets of 'V guideways and flatways

(c) Three sets of 'V guideways and flatways

(d) Four sets of 'V guideways and flatways

15. The cross-slide in a lathe moves

(a) Parallel to the axis of rotation (b) At any angle to the axis of rotation(c)

Perpendicular to the axis of rotation (d) Either 'a' or 'b'

16. The carriage in a lathe moves

(a) Parallel to the axis of rotation

(b) At any angle to the axis of rotation

(c) Perpendicular to the axis of rotation

(d) Either 'a' or 'b'

17. Which among the following parts of a lathe should have high compressive

strength?

(a) Bed (b) Main spindle

(c) Lead screw (d) Sliding gears in headstock

18. The compound slide swivel base is set at 45° to the centre line of lathe. The

degree of the reading at the cross slide index will be

(a) 135° (b)90°

(c) 45° (d)30°

19. The special gear of 127 teeth or 63 teeth may be used to cut metric threads in a

lathe having British lead screw. It is known as

(a) Idler gear (b) Change gear

(c) Translating gear (d) Compound gear

20. Which one of the following statements is true with respect to the half nut?

(a) It is detachable part of the saddle

(b) It is an integral part of the saddle

(c) It is an integral part of the apron

(d) It is detachable part of the apron

21. What is the function of the drop worm provided in the apron of the centre lathe?

(a) Engages / disengages the power feed

(b) Changes the direction of rotation of the workpiece

(c) Changes the feed direction

(d) Engages / disengages the lead screw

22. The tailstock barrel has an internal taper. Which one of the following standard

tapers is provided in the barrel bore?

(a) Metric taper (b) Morse taper

(c) Jorno taper (d) Brown and Sharpe taper

23. A jib is provided between the top slide and the swivel base assembly of the

compound slide. Its purpose is to

(a) Allowing dismantling the top slide easily

(b) Eliminate the backlash of the screw and the nut in the assembly

(c) Adjust the slackness developed due to wear

(d) Permit flow of the lubricant between the sliding surfaces

24. One of the parts of a centre lathe is tumbler gear unit. It is provided to

(a) Change the direction of feed

(b) Transmit motion from feed shaft to the carriage

(c) Change the direction of rotation of the work

(d) Alter the spindle speed

25. The graduations are marked at the base of the tailstock. To offset the body these

graduations are given in

(a) Degrees (b) Taper per foot

(c) mm (d) Radians

26. The capacity of a lathe is expressed as

(a) Horsepower and chuck diameter

(b) Swing and distance between centres

(c) Bed length and spindle speed

(d) Tool post size and lathe travel

27. The carriage of a lathe travels along which axis?

(a) "B" axis (b) "Z" axis

(c) "Y" axis (d)"X"axis

28. The basic turning lathe is

(a) Turret lathe (b) Automatic lathe

(c) Engine lathe (d) Swiss lathe

Key to Exercise - 01

1. c 2.b 3.d 4.a 5. C

6. a 7.b 8.a 9.b 10.d

11.a 12.d 13.c 14.b 15.c

16.a 17.a 18.c 19.c 20.d

21.a 22.c 23.c 24.a 25.b

26.b 27.b 28.c

Exercise-02Lathe Accessories

1. Which one of the following is used to hold cylindrical rough casting for turning?

(a) Three-jaw chuck (b) Four-jaw chuck

(c) Collet chuck (d) Magnetic chuck

2. Which one of the following centres is suitable while cutting taper by set over

method?

(a) Plain centre (b) Half centre

(c) Ball centre (d) Revolving centre

3. Which one of the following is used to hold the workpiece for machining diameter

concentric to its hole / bore?

(a) Face plate (b) Mandrel

(c) Three-jaw chuck (d) Four-jaw chuck

4. Which among the following centres is suitable when workpiece held between

centres is to be turned at high speed?

(a) Ball centre (b) Half centre

(c) Pipe centre (d) Revolving centre

5. The included angle of live centre nose is

(a) 30° (b)45°

(c) 60° (d)90°

6. A lathe half centre is used

(a) To support the workpiece always

(b) To turn long workpiece

(c) Because it is easy to lubricate the workpiece

(d) To face the workpiece upto the end of the centre hole

7. Dead centre, as compared with the live centre, bears or resists

(a) No friction (b) Equal friction

(c) Less friction (d) More friction

8. The size of three-jaw chuck is specified by

(a) The size of each jaw

(b) The thickness of each jaw

(c) The diameter of the body of the chuck

(d) Width of the body of the chuck

9. Which type of holding device is suitable for holding eccentric job

(a) Three-jaw chuck (b) Four-jaw chuck

(c) Faceplate (d) Magnetic chuck

10. A follower steady consists of

(a) One pad (b) Two pads

(c) Three pads (d) Four pads

11. A follower steady is fixed on the

(a) Tailstock (b)Bed

(c) Saddle (d)Headstock

12. The taper provided in the nose of the tailstock barrel is

(a) Morse taper (b) Jarno taper

(c) Brown and Sharpe taper (d) Metric taper

13. An irregularly shaped wotkpiece is turned on a lathe. Which one of the following

work holding accessories is used?

(a) Three-jaw chuck (b) Two-jaw chuck

(c) Driving plate (d) Faceplate

14. Which taper is used on spindle nose of the lathe headstock?

(a) Jarno taper (b) Brown and Sharpe taper

(c) Pin taper (d) Morse taper

15. What is the advantage of tailstock spindle having left-handed threads?

(a) Avoid advancement of barrel when rotated clockwise

(b) Ensure that the barrel advances with clockwise movement of hand wheel

(c) Reduce the tendency for excessive movement of the barrel

(d) Avoid jamming of spindle and hand wheel

16. Which among the following is NOT the feature of tailstock?

(a) It holds the job.

(b) Drills and reamers can be mounted on it.

(c) Dead centre is mounted on its spindle.

(d) It can be used for taper turning by offset method.

17. Which one of the following tool posts is easy for setting the tool centre height of

the tool in a lathe?

(a) Open side tool post (b) Single screw tool post

(c) Four-way tool post (d) Universal tool post

18. An angular workpiece is to be faced. It should be mounted

(a) In a three-jaw chuck (b) In a collet

(c) Between centres (d) On a face plate

19. Scroll and gear mechanism is employed in

(a) Three-jaw chuck (b) Four-jaw chuck

(c) Magnetic chuck (d) Collet chuck

20. Which among the following materials is used for steady rest pads?

(a) Mild steel (b)Lead

(c) Brass (d) Aluminium

21. Which among the following statements in respect of fixed steady is NOT correct?

(a) When setting its two lower pads are made to just touch the surface of the job

first.

(b) It must be trued before the pads to bear on the job.

(c) Skinning is done on the job before it is set with the job.

(d) It is fixed to the carriage of the lathe.

22. A fixed steady has

(a) One adjustable pad (b) Two adjustable pads

(c) Three adjustable pads (d) Four adjustable pads

23. During machining operation using faceplate, the angle plate is held on the

(a) Faceplate ' (b) Carriage

(c) Tailstock (d)Bed

24. Which one of the following methods is used to press the mandrel squarely to the

workpiece?

(a) By hammering (b) By arbor press

(c) By tailstock (d) By vice

25. Tool maker's buttons are used for

(a) Aligning the workpiece for boring to a given datum

(b) Setting the tool at correct centre height

(c) Adjusting the slackness in the guideways of cross-slide

(d) Holding the workpiece firmly

26. A faceplate is used for turning

(a) Regular shaped jobs (b) Irregular shaped jobs

(c) Flat jobs (d) None of the above

27. Which among the following statements is NOT correct?

(a) A faceplate is similar to the magnetic chuck.

(b) For accurate setting of the job on the faceplate, dial test indicator is used.

(c) To check the balance of the faceplate work, spindle drive should be

disconnected.

(d) 'V’ block is essential for holding round job on faceplate

28. ‘V’ groves of cast iron pulley have to be fine turned. Which one of the following

work holding methods gives the highest concentricity?

(a) Holding between a four-jaw chuck and a revolving centre.

(b) Holding between a three-jaw chuck and supporting with a pipe centre.

(c) Holding on a split mandrel and machining between centres.

(d) Holding on cone mandrel and machining between centres.

29. When machining an irregularly shaped workpiece held in faceplate,

counterbalancing is done by clamping weights. This is done

(a) Before mounting the faceplate on the spindle nose.

(b) After mounting the faceplate on the spindle nose and revolving the

workpiece at the slowest rpm.

(c) After mounting the faceplate on the spindle nose and keeping the spindle in

neutral position.

(d) After taking the rough cut.

30. A fixed steady rest is used to

(a) Support the tool rigidly to avoid chatter during operation.

(b) Support long shafts that are being threaded for their full length.

(c) Support workpieces during facing large diameter workpieces with short

length.

(d) Support long workpieces held in chuck, to perform operations at the

overhanging end.

31. You want to fix an irregularly shaped workpiece on a lathe, which one of the

following accessories is the most appropriate?

(a) Three-jaw self-centering chuck (b) Driving plate

(c) Faceplate (d) Catch plate

32. The fingers of a fixed steady rest are set to support a lengthy workpiece held in a

four-jaw chuck. The fingers are adjusted and set when the workpiece is

(a) Trued to the chuck and the work is stationary.

(b) Trued at the tailstock and when the work is running at slow rpm.

(c) Trued at both ends and work is stationary.

(d) Trued at both ends when the work is running at slow rpm.

33. A traveling steady is fixed at the saddle of a lathe. What is the function of this

steady rest?

(a) To prevent bending of long shafts due to cutting force.

(b) To avoid load on the lathe centres while turning long shafts.

(c) To reduce the load on the cutting tool while turning.

(d) To ensure to turn at higher cutting speeds than recommended.

34. The matching scroll threads on the back faces of the chuck jaws of a concentric

chuck are

(a) Equal in numbers but unequal in pitch.

(b) Unequal in numbers but equal in pitch.

(c) Unequal in numbers and unequal in pitch.

(d) Equal in numbers and equal in pitch.

35. A split bearing bush which has its two halves soldered, is held in a four-jaw

independent chuck for machining. Which one of the following defects will result if

the work is not held by the two opposite jaws on soldered points

(a) Truing at the chuck end is not possible.

(b) Soldering will give way and the two halves will be separated.

(c) Bored hole not concentric with outer dia. of the bush.

(d) Bored dimensional accuracy cannot be obtained.

Key to Exercise– 02

1.b 2.c 3.b 4.d 5.c

6.d 7.d 8.c 9. b 10.b

11.c 12.a 13.d 14.d 15.b

16.a 17.d 18.d 19.a 20.c

21.d 22.c 23.a 24.b 25.a

26.b 27.a 28.d 29.c 30.d

31.c 32.c 33.a 34.b 35.b

Exercise- 03Lathe Tools

1. Which one of the following tool angle is provided to avoid rubbing of the body of

the tool with the workpiece?

(a) Rake angle (b) Helix angle

(c) Clearance angle (d) None of the above

2. The negative rake angle is generally provided on the tool made of

(a) High speed steel (b) Tool steel

(c) Tungsten carbide (d) High carbon steel

3. Which one of the following is used only for finishing and maintaining correct form

of thread ?

(a) Tap (b) Threading tool

(c) Threading chaser (d) Tipped tool

4. The chip breaker on a lathe tool is essential when

(a) Turning soft material

(b) Turning ductile materials and to break the chips

(c) Turning cast iron

(d) Turning hardened materials

5. A tool, which is used to enlarge a previously drilled hole is known as

(a) Facing tool (b) Turning tool

(c) Form tool (d) Boring tool

6. What effective change will occur to the tool geometry if the cutting tool is set

below the centre height on lathe?

(a) Front clearance angle increases

(b) Front clearance angle decreases

(c) Front clearance angle remains the same

(d) Front clearance angle becomes zero

7. Inserted HSS tool bits are more useful for the operation

(a) Boring (b) External threading

(c) Internal threading (d) All the above

8. Which one of the following materials is used for manufacturing centre drills ?

(a) Cast steel (b) Mild steel

(c) High speed steel (d)Cast iron

9. Which among the following statements in respect of chasers is correct ?

(a) Chaser is a single point cutting tool

(b) Cutting threads by a chaser is slower process than that by a single point tool

(c) Cutting threads by chaser gives better finish

(d) The same chaser can be used for cutting any pitch of thread irrespective of

the type of chaser used

10. Which among the following statements in respect of the lathe cutting tools is

correct ?

(a) Red hotness temperature is higher for high carbon steel tool than that of

carbide tool

(b) The property of tool chipping off with vibration is more for cemented carbide

tools than that of HSS tools

(c) Ceramic tool has more resistance to shock as compared to HSS tool

(d) HSS tool can work at more spindle speed and feed than cemented carbide

tool

11. In the parting off tool which angle will help the tool to penetrate into the work

without rubbing at the sides ?

(a) Top rake angle (b) Front clearance angle

(c) Side clearance angle (d) Back clearance angle

12. Which among the following statements in respect of chip breakers is correct ?

(a) Chip breakers are essential for breaking the long continuous chips into small

pieces

(b) Chip breakers are necessary to break the chips to protect the finished work

surfaces

(c) Chip breakers are provided to curl and break the chips

(d) All the above

13. Helix angle is found on

(a) feed rod of lathe (b) threading tool

(c) threaded workpiece (d) taper turning attachment

14. The width of the tool used to cut 10 mm pitch square thread is

(a) 10 mm (b)7.5mm

(c) 5 mm (d) 2.5 mm

15. The included angle of the countersinking portion of a centre drill of type 'B' used

for protecting the centre hole is

(a) 75° (b)90°

(c) 100° (d)120°

16. Which one of the following factors will NOT influence the selection of the cutting

speed ?

(a) Diameter of the workpiece (b) Workpiece material

(c) Tool material (d) Operation to be performed

17. Which one of the following angles of rough turning tool, depends upon the feed

rate chosen ?

(a) Top rake angle (b) Side rake angle

(c) Front clearance angle (d) Side clearance angle

18. The size of the centre drill is selected on the basis of the

(a) length of the workpiece (b) material of the workpiece

(c) diameter of the workpiece

(d) operation to be performed on the workpiece

19. Taps are surface treated to

(a) improve the appearance

(b) improve the wear resistance property

(c) prevent them from getting corroded

(d) be used only on automatic threading machines

20. Chip breakers are meant to break continuous long chips. Which one of the

following types of chip breakers is found on a throw away insert with holder ?

(a) Piece of sheet metal clamped to the holder in the path of the coil

(b) A step is ground on the throw away insert along the cutting edge

(c) A small groove ground at the cutting edge

(d) A carbide bit is screwed and held on the top face of the bit

21. To enable a nut to fit properly on a bolt of square threads, the width of the internal

square threading tool should be

(a) slightly more than the half pitch (b) slightly less than the half pitch

(c) equal to the half pitch (d) equal to the pitch

22. The tip of a cemented carbide tool is joined on the shank by

(a) welding (b) brazing

(c) soldering (d) clamping with a screw

23. Which one of the following materials for lathe cutting tools can be forged to any

desired shape ?

(a) High speed steel (b) High carbon steel

(c) Stellite (d) Tungsten carbide

24. When rough turning a workpiece with a carbide tool long curly chips are formed.

Which one of the following is the right way of getting rid of this kind of chip ?

(a) Stop the power feed at intervals so that the chip breaks

(b) Change the rake angle

(c) Provide chip breaker on the tool

(d) Use a metal hook and pull away the chips

25. A brass shaft is to be turned to a surface roughness Ra = 0.8, with high cutting

speed. Which one of the following cutting tool materials is most suitable ?

(a) High speed steel (b) High carbon steel

(c) Low alloy steel (d) Cemented carbide

26. Which one of the following statements is true with reference to the tool life ?

(a) Time between starting and finishing a job

(b) Total time for turning work including regrinding of tool

(c) Time between two successive regrinds

(d) Time between starting of metal cutting and tool wear out

27. A carbide tipped tool with blue marking is used on a lathe. Which one of the

following materials can be machined with this tool ?

(a) Brass (b) Steel

(c) Plastic (d) Grey cast iron

28. Hand chasers are used for

(a) quick production of threads

(b) cutting threads on soft metal directly

(c) rectifying threads cut on steel rods which are distorted

(d) rectifying crest and root of threads formed by single point tool

Key to Exercise -03

1.c 2.c 3.c 4.b 5.d

6.a 7.d 8.c 9.c 10.b

11.d 12.d 13.c 14.c 15.d

16.a 17.d 18.c 19.b 20.d

21.a 22.b 23.b 24.c 25.d

26.c 27.b 28.c

Exercise -04 Lathe Operations

1. Which one of the following is the correct position of threading tool to cut V-

thread?

(a) Exactly at centre height of the workpiece with toolaxis perpendicular to the

workpiece axis

(b) Exactly at centre height of the workpiece with toolaxis at 60° to the workpiece

axis

(c) Exactly at centre height of the workpiece with toolaxis at 45° to the workpiece

axis

(d) Exactly at centre height of the workpiece with toolaxis at 30° to the workpiece

axis

2. Which among the following statements is suitable to get better finish by turning ?

(a) Increase the speed and feed

(b) Reduce the speed and feed

(c) Increase the speed and reduce the feed

(d) Increase the feed and reduce the speed

3. For plain turning a 60 mm diameter workpiece using HSS tool with recommended

cutting speed of 30 metre / min., the rpm should be

(a) 80 rpm (b)159 rpm

(c) 192 rpm (d) 318 rpm

4. Which among the following factors governs the selection of feed when turning a

workpiece ?

(a) Tool geometry (b) Surface finish required

(c) Type of coolant required (d) All of the above

5. Which one of the following shoulders is used on components to be threaded ?

(a) Square shoulder (b) Radius shoulder

(c) Undercut shoulder (d) Beveled shoulder

6. State the direction of rotation of job and lead screw while cutting left hand thread

viewing from tailstock end. (CW = clockwise; ACW = anticlockwise).

(a) Both the job and lead screw rotate CW

(b) Both the job and lead screw rotate ACW

(c) Job rotates CW and lead screw rotates ACW

(d) Job rotates ACW and lead screw rotates CW

7. Fine facing is done by feeding the tool

(a) from centre to the periphery of the job

(b) from periphery to the centre of the job

(c) either 'a' or 'b'

(d) neither 'a' nor 'b'

8. Which one of the following types of chips is found while turning cast iron ?

(a) Long curly chips (b) Segmental chips.

(c) l-shaped chips (d) Spiral chips

9. While step turning, it is preferred to turn first

(a) small diameter step (b) large diameter step

(c) either 'a' or 'b' (d) neither 'a' nor 'b'

10. As the diameter of the workpiece decreases, the spindle speed (for the same

cutting speed)

(a) increases (b) decreases

(c) remains the same (d) none of the above

11. The difference in measurement between the machined and un-machined

diameter is equal to the

(a) depth of cut (b) ½ depth of cut

(c) 2 x depth of cut (d) none of the above

12. Centre drilling should be done at

(a) higher rpm with a slower feed (b) higher rpm with a higher feed

(c) slower rpm with a higher feed (d) slower rpm with a slower feed

13. Which among the following is the cause for incorrect pitch of thread during thread

cutting with single point tool?

(a) Incorrect selection of change gears (b) Lead screw worn out

(c) Half nut worn out (d) Any one of the above

14. Which one of the following is the reason for torn threads while thread cutting on

lathe ?

(a) Blunt tool (b) Heavy depth of cut

(c) Insufficient side clearance (d) Any one of the above

15. For setting of tool for threading, it is aligned with the work by using

(a) try square (b) centre gauge

(c) thread plug gauge (d) template

16. Which among the following statements in respect of threads/ thread cutting is

NOT correct ?

(a) Threading tools are checked for accuracy for the 60° angle by using a centre

gauge

(b) M 10 x 1.25 is a fine pitch thread

(c) M 10 is a coarse pitch thread

(d) Same tool is used for cutting external and internal threads

17. While cutting internal threads on lathe with single point tool, the spindle speed

should be

(a) less than that for the plain turning operations

(b) more than that for the plain turning operation

(c) equal to that for plain turning operation

(d) None of the above

18. Which one of the following statements in respect of thread cutting is NOT

correct?

(a) Inserted tool bits are more advantageous while cutting internal threads

(b) Before cutting internal threads, the hole should be chamfered

(c) When internal thread cutting is done in a blind hole, a recess should be

provided

(d) When cutting internal threads, the core diameter may be equal to the size of

external threads

19. Which among the following in respect of thread cutting is NOT correct ?

(a) The threads can be cut on a lathe by using simple gear train arrangement

only

(b) The 127 teeth gear is used as driven gear for cutting metric threads on a

lathe having lead screw in TPI

(c) The 63 teeth gear is used as a driver for cutting British threads on a lathe

having metric lead screw

(d) The teeth of the driver and driven are based on the pitch of thread to be cut

and the pitch of thread on lead screw

20. Which one of the following statements in respect of eccentric turning is correct ?

(a) In an eccentric shaft, the centres of the individual diameters are displaced

(b) Eccentric shaft can be turned by holding it in a three-jaw chuck

(c) Higher speed is chosen for eccentric turning

(d) It is preferred to give more depth of cut in the beginning while turning an

eccentric shaft

21. Which one of the following statements in respect of thread chasing dial is NOT

correct ?

(a) Thread chasing dial is used to catch the thread when threading on lathe

(b) Worm gear of chasing dial engages with the lead screw while thread chasing

(c) Thread chasing dial is an additional part of the lathe carriage

(d) Thread chasing dial stops rotating when the half nut lever is engaged

22. If the pitch to be cut is 2.5 mm and the lathe has 5 mm pitch lead screw, the

thread chasing dial has 8 divisions and a 16 teeth worm wheel fitted on it, the

engagement of half nut should be

(a) only at one particular position (b) only at numbered or un-numbered division

(c) at opposite position (d) anywhere

23. Which among the following statements is correct ?

(a) During turning, after giving one depth of cut, the diameter is reduced equal

to double the depth

(b) Carbide tipped tool can withstand shock load

(c) When turning bigger diameter job, the rpm is proportionally increased

(d) When turning smaller diameter job, the rpm is proportionally decreased

24. A 24-teeth gear is fixed at stud as driver gear. After completion of first start and

before starting of second start, the driver gear should be turned

(a) 24 teeth (b) 18 teeth

(c) 12 teeth (d) 6 teeth

25. A simple gear train is to be used to cut a thread with a certain pitch. A driver gear

with 3 teeth more than that of the calculated value is mounted due to the non-

availability of the required gear from the set. The thread that is cut will have the

pitch

(a) More than that required throughout the length

(b) Less than that required throughout the length

(c) Equal to that required throughout the length

(d) More for a certain length and then less for the remaining length

26. Power feed is not possible in compound slide method of taper turning. Which

one of the following defects can be noticeable on the tapered workpiece due to

the above reason ?

(a) Chatter (b) Poor surface finish

(c) Taper angle more than set (d) Taper angle less than set

27. To get a fine even surface on a workpiece by facing operation on lathe, it is

necessary to have

(a) low cutting speed, fine feed and heavy depth of cut

(b) low cutting speed, fine feed and light depth of cut

(c) high cutting speed, fine feed and light depth of cut

(d) high cutting speed, fine feed and heavy depth of cut

28. Which one of the following operations is NOT done on a workpiece held in-

between centres ?

(a) Knurling (b) Undercutting by plunging

(c) Thread cutting (d) Parting off

29. Which one of the following methods of catching the threads consumes more time

when cutting odd pitch threads ?

(a) Using thread-chasing dial

(b) Reversing the machine

(c) Marking the work holding device and lead screw

(d) Pre-determined travel of the carriage

30. A hole is drilled in a lathe by using a 10 mmdia straight shank drill held in a drill

chuck. After a short distance of the drill travel, it rotates along with the work.

Which one of the following is the cause for this defect ?

(a) Chips getting clogged

(b) Centre not aligned

(c) Spotting at the centre not done

(d) Feeding by tailstock hand wheel is too slow

31. Unusual sound is heard during rough boring a large diameter hole. Which one of

the following statements is the cause for this defect ?

(a) Boring tool springs its travel

(b) Coolant is not applied with force

(c) Tool set below centre

(d) No secondary clearance ground on the front cutting edge

32. A workpiece is chamfered to remove burrs. It is observed that the chamfer width

is not uniform throughout the periphery of chamfer on a workpiece. Which one of

the following is the cause for this defect?

(a) The angle of chamfering is not correct

(b) The chamfering tool not set square to the work axis

(c) The work face not running true

(d) The overhang of the tool is too much

33. By which one of the following, a multi-start thread is cut on a lathe ?

(a) By a chaser (b) By a die head

(c) By a single-point tool (d) By a split die

34. If the lead screw has 6 TPI and there are 4 numbered divisions in the chasing

dial, which one of the following will be the teeth worm wheel of chasing dial ?

(a) 48 teeth (b) 24 teeth

(c) 18 teeth (d) 12 teeth

35. While thread cutting on a lathe by using single-point tool, the tool moves in a path

called as

(a) Epicycloid (b) Cycloid

(c) Rake (d) Helix

36. Which one of the following diameters of the workpiece should be turned before

cutting external threads ?

(a) Major diameter (b) Core diameter

(c) Pitch diameter (d) Head diameter

37. When the threading tool reaches the end of the thread, the tool should be

(a) left in the groove and reverse the workpiece

(b) withdrawn after stopping the machine

(c) withdrawn while the tool is taking cut

(d) withdrawn after removing the workpiece

38. A shaft of 50 mm has to be rough turned to 0 42 mm in one pass. When will you

check to ensure the set depth of cut is correct ?

(a) After the tool traveled the full length

(b) After the tool traveled half way

(c) Just after the cut is taken at the tailstock end -

(d) After the tool has traveled a distance more than the angular shoulder

39. A M30 thread is rough cut using a thread roughing tool. Which one of the

following is the correct procedure for aligning the finishing tool with the thread

groove ?

(a) Work stationary, tool adjusted and positioned in the groove by compound

slide and cross slide

(b) Work stationary, tool adjusted and positioned in the groove by carriage hand

wheel and cross slide hand wheel

(c) Work revolving, half nut engaged, tool positioned in the groove by compound

slide and cross slide

(d) Work revolving, half nut engaged, tool positioned in the groove by carriage

and cross slide hand wheels

40. Which one of the following is a remedial measure to prevent the tool cutting edge

chipping off?

(a) Increase feed rate (b) Reduce cutting speed

(c) Decrease nose radius (d) Use negative top rake

Key to Exercise -04

1.a 2.c 3.b 4.d 5.c

6.d 7.c 8.b 9.c 10.a

11.c 12.a 13.b 14.d 15.b

16.d 17.a 18.d 19.a 20.a

21.c 22.d 23.a 24.c 25.a

26.b 27.c 28.d 29.c 30.a

31.a 32.c 33.c 34.b 35.d

36.a 37.c 38.d 39.c 40.d

Exercise -05 Screw Threads

1. The distance through which a screw thread advances axially in one turn is called:

(a) Pitch of thread (b) Lead of thread

(c) Depth of thread (d) Diameter of thread

2. The pitch of 3-start thread is the lead divided by

(a) 1 (b)2

(c) 3 (d)4

3. The angle of I.S. thread (V-shaped) is

(a) 29° (b)471/2°

(c) 50° (d)60°

4. What type of threads are suitable for small precision components and measuring

gauges ?

(a) British Association threads (b) Whitworth Screw threads

(c) Acme threads (d) Square threads

5. What type of threads are suitable for lead screws of machine tools ?

(a) British Association threads (b) Whitworth Screw threads

(c) Acme threads (d) Square threads

6. Which one of the following is the reason for rough and broken threads ?

(a) Thread cutting tool blunt.

(b) The size of hole or diameter of the blank for bolt is not correct.

(c) The flutes of cutting tool are filled with chips.

(d) All the above.

7. The distance between one point on a screw thread and the corresponding point

on the next thread, measured parallel to the axis is called as

(a) Axis of thread (b) Depth of thread

(c) Pitch of thread (d) Lead of thread

8. In a single start thread

(a) Lead and pitch are equal (b) Lead is double the pitch

(c) Pitch is double the lead (d) Lead is half the pitch

9. Which one of the following screw thread forms has an included angle of 29°

between the flanks of thread ?

(a) B. A. thread (b) Acme thread

(c) Buttress thread (d) Knuckle thread

10. The pitch diameter of the external screw thread is checked by

(a) Screw pitch gauge (b) Thread ring gauge

(c) Screw thread micrometer (d) Vernier caliper

11. A screw thread is formed on a cylindrical surface by cutting

(a) Helical grooves (b) V-grooves

(c) Square grooves (d) Half round grooves

12. The root of ISO metric thread is

(a) Flat (b) Round

(c) Sharp corner (d) None of the above

13. Which one of the following thread forms is used in a threaded assembly where

the sliding force acts in one direction only ?

(a) Square thread (b) V thread

(c) Saw-tooth thread (d) Knuckle thread

14. B.S.F. screw threads have the included angle of

(a) 30° (b)45°

(c) 55° (d)60°

15. The depth of B.A. screw thread is

(a) 0.64 P (b) 0.7035 P

(c) 0.6 P (d)0.61 P

16. The pitch diameter of a screw thread is the

(a) Nominal diameter of the rod

(b) Imaginary diameter in between the major and minor diameter of the thread

(c) Minimum diameter of the thread

(d) Maximum diameter of the thread

17. B.S.F. screw threads are generally used for

(a) Ordinary bolts and nuts (b) Electrical goods

(c) Lathe lead screw (d) Vice spindle

18. Which one the following threads, is used on mechanical jack?

(a) Acme (b) Square

(c) Buttress (d) B.S.F.

19. Screw threads are produced without metal removing by a process called as

(a) Thread cutting (b) Thread chasing

(c) Thread rolling (d) Tapping

20. Which one of the following thread forms on bolts and nuts is meant for general

fastening purposes ?

(a) 'V’ threads (b) Square threads

(c) Knuckle threads (d) Acme threads

21. Which one of the following screw thread elements is NOT checked with the

thread ring gauge ?

(a) Pitch diameter (b) Pitch

(c) Helix angle (d) Profile

22. Which one of the following elements of an internal screw thread cannot be

measured directly with precision instruments ?

(a) Width of crest (b) Minor diameter

(c) Major diameter (d) Pitch diameter

23. Which one of the following statements is correct with respect to the spiral fluted

taps ?

(a) Used to tap oversized hole (b) Used to tap holes with slots

(c) The tap tends to push the chips ahead of the tap

(d) Threads formed by displacing the work material

24. The shape of the frame of thread snap gauge is in theform of

(a) Round (b) Square

(c) 'Y'type (d)"C"type

25. The shape of the thread in the 'Not Go' end of a thread snap gauge is

(a) Beveled (b) Truncated

(c) Taper (d) Sharp

26. The handle of thread plug gauge is made from ebonite material for

(a) reducing the cost (b) reducing the weight

(c) easy manufacturing (d) easy handling

27. Which one of the following thread groups is only for transmitting motion ?

(a) Square, Modified square, Acme, Buttress threads

(b) Whitworth, Acme, Square, Buttress threads

(c) Unified, Acme, Square threads

(d) ISO Metric, Modified Square, Acme threads

28. Buttress threads are most commonly used for

(a) Transmission of motion (b) Resisting force exerted in one direction only

(c) Positioning of mechanical parts (d) Special bolts and units in structural work

29. While threading on lathe, the carriage is moved by means of

(a) Lead screw (b) Hand wheel

(c) Feed rod (d) Gear train on a rack

30. The depth of Indian Standard (BIS) thread is

(a) 0.6495 P (b) 0.6000 P

(c) 0.6403 P (d) 0.6134 P

31. Threads are cut on a lathe with a single point tool by

(a) Setting the correct speed

(b) Setting on cut for the full depth of the thread.

(c) Making a series of cuts in the same cut.

(d) Moving the carriage by means of rack.

32. Which one of the following thread forms is mostly found on threaded shaft of

lifting equipment for carrying loads?

(a) V thread (b) Square thread

(c) Saw tooth thread (d) Knuckle thread

33. In a threaded assembly the contact between the male and female threads takes

place on the

(a) Pitches (b) Flanks

(c) Crests (d) Roots

Key to Exercise -05

1.b 2.c 3.d 4.a 5.c

6.d 7.c 8.a 9.b 10.c

11.a 12.b 13.c 14.c 15.c

16.b 17.b 18.b 19.c 20.a

21.a 22.d 23.b 24.d 25.b

26.b 27.a 28.b 29.a 30.d

31.c 32.b 33.b

Exercise -06Grinding

1. Dressing and truing of a grinding wheel are

(a) exactly the same operation

(b) done with the same equipment

(c) done only for coarse grinding wheels

(d) only for form grinding wheels

2. A hardened die block (work) has to be ground. It is required to retain the same

hardness even after grinding. If the work is overheated in the grinding process, it

may result in work being rejected or scrapped. Probable reason for rejection is

that the work surface is

(a) discoloured (b) softened

(c) rough (d) brittle

3. What is the trouble when grinding wheel fails to cut in a grinding machine ?

(a) Grinding wheel's grade is too soft (b) Grinding wheel is glazed

(c) Grinding wheel is not securely mounted on spindle

(d) Too much feed is given

4. The depth of infeed per pass in dressing a grinding wheel should be not more

than

(a) 0.25 mm (b) 0.025 mm

(c) 0.0025 mm (d) 0.00025 mm

5. The grade of a grinding wheel is specified by letters from A to Z. Which are of the

following refers to the hardest grade?

(a) E (b)J

(c) P (d)Y

6. It is required to finish grind a 050 mm mild steel shaft on a cylindrical grinding

machine. What will be the surface speed if r.p.m. of the job is 191 ?

(a) 20 metres/min. (b)25 metres/min.

(c) 30 metres/min. (d) 35 metres/min.

7. Which among the following is the natural abrasive ?

(a) Corrundum (b) Diamond

(c) Emery (d) All of the above.

8. By which unit the roughness value is expressed for grinding

a. µm b.µin. c.µlbs d.µft.

Key to Exercise -06

1.b 2.b 3.b 4.b 5.d

6.c 7.d 8.a

Exercise -07 Metals

1. Which one of the following range of carbon content ispresent in pig iron?

(a) 0.05 to 1.4% (b) 0.9 to 1.4%

(c) 1.7 to 2.2% (d)3to5%

2. What is the name of the furnace, which is used for themanufacture of C.I. ?

(a) Open hearth (b)Cupola

(c) Bessemer (d) Puddling

3. The main product of puddling furnace is

(a) Cast iron (b) Wrought iron

(c) Cold rolled steel (d) Hot rolled steel

4. Pig iron is product of

(a) Cuploa furnace (b) Blast furnace

(c) Open hearth furnace (d) Electric arc furnace

5. Which one the following processes can produce highalloy steel with accurately

specified chemicalcomposition?

(a) Bessemer process (b) Open hearth furnace

(c) Electric arc process (d) Crucible process

6. A black malleable cast iron

(a) Is a raw casting

(b) Can be worked with hard cutting tools

(c) Which through malleablizing and is decarburized at the outer skin

(d) Is steel cast in moulds.

7. Which one of the following elements, influences most of the forgeability of steel ?

(a) Silicon (b) Manganese

(c) Carbon (d) Nitrogen

8. In case of steel, through which one of the following processes, there will be no

increase in hardness ?

(a) Heating above 600°C and slow cooling (b) Rolling

(c) Hammering (d) Alloying with chromium

9. Grey cast iron has

(a) High compressive strength (b) Low compressive strength

(c) High tensile strength (d) Low tensile strength

10. Main alloying element in H.S.S. is

(a) Tungsten (b) Chromium

(c) Vanadium (d) Nickel

11. Carbon percentage in HSS tool is

(a) 0.75 to 1.00% (b) 1.00 to 2.00%

(c) 0.60 to 0.75% (d) 0.20 to 0.30%

12. The commonly used proportions of alloying elementsin HSS are

(a) 18% tungsten, 4% chromium and 1% vanadium

(b) 18% chromium, 4% tungsten and 1% vanadium

(c) 18% vanadium, 4% chromium and 1% tungsten

(d) 18% cobalt, 4% chromium and 1% vanadium

13. Grey cast iron is

(a) Malleable (b) Ductile

(c) Tensile (d) Rigid

14. Which one of the following metals has less carbon content?

(a) Plain carbon steel (b) Wrought iron

(c) Pig iron (d) Cast iron

15. A brass shaft is to be finish turned to a surface roughness Ra = 0.8, with high

cutting speed. Which one of the following cutting tool materials is suitable for this

purpose?

(a) H.S.S. (b) High carbon steel

(c) Low alloy steel (d) Cemented carbide

16. A solid forged boring tool is made of

(a) H.S.S. (b) Tungsten carbide

(c) Stellite (d) Cast iron

17. Solid milling cutters are manufactured from

(a) Sintered carbide (b) H.S.S.

(c) Ceramic (d) Stellite

18. Which one of the following is an alloy of iron and carbon?

(a) Pig iron (b) Cast iron

(c) Wrought iron (d) Steel

Key to Exercise– 07

1.d 2.b 3.b 4.b 5.c

6.a 7.c 8.a 9.a 10.a

11.a 12.a 13.d 14.b 15.d

16.a 17.b 18.d

Exercise –08Preventive Maintenance

1. Lubricant is necessary to

(a) Run the machine smoothly taking least load.

(b) Run the machine quickly.

(c) Stop the machine immediately.

(d) Produce workpiece of greater accuracy.

2. The general ratio of soluble oil and water used as coolant is

(a) 10:1 (b)1:10

(c) 1:20 (d)20:1

3. The best example for semi-liquid lubricant is

(a) Grease (b) Graphite

(c) Castor oil (d) Lard oil

4. Best example for gravity feed lubrication is

(a) Grease gun (b) Ring lubricator

(c) Tell-tale lubricator (d) Wick feed lubricator

5. Most common type of cutting fluid used in almost all the machining operation is

(a) Water (b) Lard oil

(c) Soluble oil (d) Compressed air

6. Fire point is

(a) The temperature at which an oil gives off sufficient vapour to burn it

continuously when ignited.

(b) The temperature at which an oil will cease to flow when cooled.

(c) The lowest temperature at which an oil gives off sufficient vapour to support a

momentary flash without actually setting fire.

(d) The temperature at which fire is produced.

7. Graphite is a

(a) Liquid lubricant (b) Semi-liquid lubricant

(c) Solid lubricant (d) None of the above

8. The best example for splash lubrication is

(a) Ring lubricator (b) Wick feed lubricator

(c) Grease gun (d) Pump lubricator

9. Slideways of a machine are frequently lubricated by

(a) Oilcan (b) Grease gun

(c) Ring lubricator (d) Wick feed lubricator

10. Which one of the following is the reason that tap water is not preferred as coolant

on machine tools?

(a) It decreases cutting action of the tool.

(b) Danger of corrosion.

(c) It has insufficient cooling effect.

(d) Due to high cooling effect the cutting edges of tool break off.

11. Which one of the following frictions occurs in an un-lubricated journal bearing ?

(a) Sliding friction (b) Rolling friction

(c) Fluid friction (d) Dry friction

12. In which one of the following materials no cutting oil is used when drilling ?

(a) Tool steel (b) Grey cast iron

(c) Copper (d) Aluminium

13. Preventive maintenance is

(a) The overall lubrication and repair work carried out by the maintenance

section in advance of the machine coming to breakdown.

(b) The maintenance work for any fault noticed during the work.

(c) Done to prevent the maintenance of machines.

(d) None of the above.

14. For effective cutting of steel with hand hacksaw, which one of the following

coolant is suitable?

(a) Cutting oil (b) Grease

(c) Lard oil (d) Kerosene oil

15. Leveling bolts are used for

(a) Supporting the load for machine (b) Adjusting the height of machine

(c) Rigidity of machine (d) None of the above

16. Which one of the following tests is carried out after overhauling and

reconditioning of machines ?

(a) Periodic acceptance test (b) Geometrical test only

(c) Performance test only (d) None of the above

17. The permissible deviation for leveling of machine is

(a) 0.03/100 mm (b) 0.03 / 200 mm

(c) 0.03 / 300 mm (d) 0.03 / 400 mm

18. Which one of the following is used for checking run out of the internal taper of

machine spindle ?

(a) Dial test indicator

(b) Test mandrel and dial test indicator

(c) Precision height gauge

(d)Test mandrel and precision height gauge

19. The sensitivity of precision spirit level is

(a) 0.02 to 0.05/100 mm (b) 0.02 to 0.05 / 200 mm

(c) 0.02 to 0.05 / 500 mm (d) 0.02 to 0.05 /1000 mm

20. Which among the following is NOT the purpose of a grease?

(a) Carry away heat produced in bearing.

(b) Prevent metal-to-metal contact and reduce friction.

(c) Prevent entry of foreign material i.e. dust, dirt etc. in the bearing.

(d) Provide a cushion to a load and shocks.

21. Which one of the following is NOT the property of a good lubricant ?

(a) No change in viscosity due to variation in temperature.

(b) Reduces friction between machine parts.

(c) Takes up the surface pressure between sliding parts.

(d) Becomes thicker after prolonged use.

22. A concrete mixture ratio is given as 1 : 2 : 4. Which one of the following indicates

these numbers ?

(a) One part cement, two parts sand and four parts stone.

(b) One part stone, two parts cement and four parts sand.

(c) One part sand, two parts stone and four parts cement.

(d) One part cement, two parts stone and four parts sand.

23. The most important quality of any lubricant is

(a) Viscosity (b) Specific gravity

(c) Specific heat (d)Emulsification

24. Which one of the following is the best way for preparing an emulsion ?

(a) Mix soluble oil and water by pouring both simultaneously

(b) Add water to the soluble oil

(c) Add soluble oil to the water

(d) None of the above

25. Which one of the following is common method for applying cutting fluid on the

tool point ?

(a) With high pressure jet (b) With a brush

(c) With an oil can (d) Either 'b' or 'c'.

26. While machining cast iron, the coolant used should be

(a) Dry air (b) Kerosene

(c) Machine oil (d) Soft water

Key to Exercise–08

1.a 2.c 3.a 4.d 5.c

6.c 7.c 8.a 9.a 10.b

11.d 12.b 13.a 14.a 15.b

16.a 17.c 18.b 19.d 20.a

21.d 22.a 23.a 24.c 25.a

26.a

Exercise –09Miscellaneous Practice Questions

1. The use of pipe reamer is:

(a) to make OD of the pipe smaller (b) to remove the burr

(c) to make ID of the pipe bigger (d) to make threading

2. The diameter of the best sized wires, in the three wire measurement of pitch

diameter of an external screw thread depends upon

(a) major diameter, pitch and helix angle

(b) major diameter, pitch and thread angle

(c) pitch and helix angle

(d) pitch and thread angle

3. Rake angle is not provided on a form tool used to produce taper on a

workpiece. The reason for this is

(a) to reduce grinding time of the tool

(b) to reduce wastage of tool material

(c) taper angle is not affected by re-sharpening

(d) for the tool to have large wedge angle

4. A simple change gear train is used to cut a certain pitch thread. Due to the non-

availability of the required gear from the set, down gear with 3 teeth more than

that of the calculated value is mounted.The thread that is cut will have a pitch

(a) more than that required for the full threaded length

(b) less than that required for the full threaded length

(c) equal to that required for the full threaded length

(d) more for certain length and then less for the remaining thread length

5. A rough turning tool is ground by hand on a pedestal grinder. After grinding it is

observed that the ground faces of the tool are concaved. Which one of the

following statements is the cause for this defect?

(a) Tool rest not set to the required angle

(b) Tool held in one position only against the wheel

(c) Surface speed of the grinding wheel is not asspecified

(d) The grinding is carried out on a peripheral grindingwheel

6. Which one of the following standard tapers is self-holding type ?

(a) Morse taper (b) Brown and Sharpetaper

(c) Jarno taper (d) Metric taper

7. The amount of offset of tailstock for taper turning is done by the offset screws

provided. The procedure to be followed is

(a) Loosen both screws and push the body to the amount of offset

(b) Loosen both the screws and push the base to the amount of offset

(c) Loosen the screw opposite to the direction of movement and tighten the

other screw

(d) Loosen the screw in the direction of movement and tighten the other screw

8. Single point metric 'V threading tools are checked for its flank angle accuracy

by using a

(a) thread plug gauge (b) centre gauge

(c) screw pitch gauge (d) tool angle gauge

9. You have to cut threads on aluminium. Which one of the following coolants will

you use?

(a) Lard oil (b) Kerosene

(c) Soluble oil (d) Vegetable oil

10. Different threads have got different depths. Which one of the following has got

the highest depth ?

(a) Square (b)Acme

(c) Worm (d) Buttress

11. The standard taper of taper pin is

(a) 1 : 20 (b) 1 : 30

(c) 1 : 40 (d) 1 : 50

12. Which taper is used on spindle nose of the lathe headstock?

(a) Jarno taper (b) Brown and Sharpetaper

(c) Pin taper (d) Morse taper

13. The most favourable metal for chemical plants and food processing equipment

is stainless steel because it has high corrosion resistance at

(a) atmospheric temperature only (b) high humidity

(c) high electrical current (d) elevated temperatures

14. Which jig is used for drilling on thin sheet?

(a) Solid jig (b) Sandwich jig

(c) Post jig (d) Table jig

15. Carbide tipped tool used for turning hard material is provided ....

(a) Side rake angle (b) Zero rake angle

(c) Positive rake angle (d) Negative rake angle

16. The plastics which formed to shape by the application of heat and pressure

without any chemical change are known as ....

(a) Thermosetting plastics (b) Thermoplastics

(c) Elastomers (d) Aminos

17. The value of one thimble scale division in a metric micrometer is ...

(a) 1 mm (b)0.5 mm

(c) 0.02 mm (d)0.01 mm

18. The main purpose of screw pitch gauge is...

(a) To check the minor diameter of screw thread

(b) To check the limits of screw thread

(c) To check the distance between adjacent crests ofscrew threads

(d) To check the major diameter of screw thread

19. The soft material particles get clogged in the grinding wheel while grinding. This

is called...

(a) Truing (b) Loading

(c) Glazing (d) Dressing

20. The faces of anvil and spindle of outside micrometer is made of...

(a) Cast iron (b) Steel

(c) Tungsten carbide (d) Aluminium alloy

21. Which one of the following formula is applied to find the tail stock offset, when

turning tapers by offset method ?

(a)I

dD (b)

I

dD

2

(c) LXI

Dd

2

(d) I

Dd

2

22. What is the most suitable size of rod for M6 threading?

(a) 6 mm (b) 5.9 mm

(c) 5.6 mm (d) 5.2 mm

23. Best conductor of heat and electricity is

(a) Nickel (b) Copper

(c) Chromium (d) Aluminium

24. Which machine reamer has guides on front and rear sides?

(a) Jig reamer (b) Rose reamer

(c) Shell reamer (d) Chucking reamer

25. In a vernier micrometer, vernier scale is graduated on...

(a) thimble (b) spindle

(c) barrel (d) frame

26. Calculate the tap drill size in mm to tap M12 X 1 thread...

(a) 9.6 mm (b)10.8 mm

(c) 11.38 mm (d) 11.62 mm

27. Which range of cutting speed is suitable for turning mild steel using H.S.S. tool?

(a) 15-20m/min (b) 35 - 50 m/min

(c) 50-80m/min (d) 70 - 100 m/min

28. What coolant is used for drilling the aluminium job?

(a) Dry air (b) Kerosene

(c) Soluble oil (d) Mineral oil

Key to Exercise–09

1.c 2.d 3.c 4.b 5.

6.a 7.c 8.c 9.b 10.c

11.d 12.d 13.d 14.b 15.d

16.b 17.d 18.c 19.b 20.c

21.c 22.b 23.b 24.a 25.c

26.b 27.b 28.b