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 tool axis perpendicular to the
workpiece axis
(b) Exactly at centre height of the workpiece with tool axis at 60° to the workpiece axis
(c) Exactly at centre height of the workpiece with tool axis at 45° to the workpiece axis
(d) Exactly at centre height of the workpiece with tool axis 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 mm dia 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
Answers Key-
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
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