TN 12th Question Paper 2025 Basic Mechanical Engineering

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8376
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Part III — Vocational Subjects
Ai¨£øh C¯¢vµÂ¯À - -P¸zv¯À
BASIC MECHANICAL ENGINEERING - THEORY
( uªÌ ©ØÖ® B[Q» ÁÈ / Tamil & English Version )

Põ» AÍÄ : 3.00 ©o ÷|µ® ] [ ö©õzu ©v¨ö£sPÒ : 90
Time Allowed : 3.00 Hours ] [ Maximum Marks : 90

AÔÄøµPÒ : (1) AøÚzx ÂÚõUPЮ \›¯õP £vÁõQ EÒÍuõ GߣuøÚ \›£õºzxU
öPõÒÍÄ®. Aa_¨£vÂÀ SøÓ°¸¨¤ß AøÓU PsPõo¨£õÍ›h®
EhÚi¯õPz öu›ÂUPÄ®.
(2) }»® AÀ»x P¸¨¦ ø©°øÚ ©mk÷© GÊxÁuØS®
AiU÷PõikÁuØS® £¯ß£kzu ÷Ásk®. £h[PÒ ÁøµÁuØS
ö£ß]À £¯ß£kzuÄ®.
Instructions : (1) Check the question paper for fairness of printing. If there is any lack of fairness,
inform the Hall Supervisor immediately.
(2) Use Blue or Black ink to write and underline and pencil to draw diagrams.

£Sv & I / PART - I

SÔ¨¦ : (i) AøÚzx ÂÚõUPÐUS® Âøh¯ÎUPÄ®. 15x1=15

(ii) öPõkUP¨£mkÒÍ |õßS ©õØÖ ÂøhPÎÀ ªPÄ® Hئøh¯
Âøhø¯ ÷uº¢öukzx SÔ±mkhß Âøh°øÚ²® ÷\ºzx GÊuÄ®.

Note : (i) Answer all the questions.

(ii) Choose the most appropriate answer from the given four alternatives and write
the option code and the corresponding answer.

[ v¸¨¦P / Turn over

8376 2

1. \›Ä E¸øÍ ö\´¯ £¯ß-£-k® £õ-P® :
(A) ÷\iÀ (B) SÖUS |Ê-Â
(C) H¨-µõß (D) Põ®-ö£Ísm öµìm
A part used for taper turning :

(a) Saddle (b) Cross slide

(c) Apron (d) Compound rest

2. Pøh-\À C¯¢-v-µz-vÀ £¯ß-£-kz-u¨-£-k® öÁm-kÎ :
(A) µ®-£¨ -£À öPõsh öÁm-k-Î (B) £» •øÚ öÁm-k-Î
(C) xs-k-£-kz-x® öÁm-kÎ (D) J¸ •øÚ öÁm-k-Î
The tool used in lathe is a :
(a) Slitting saw tooth cutting tool (b) Multipoint cutting tool
(c) Parting tool (d) Single point cutting tool

3. xøÍ-°-k® A»-QÀ EÒÍ £ÒÍz-vß ö£¯º :
(A) _¸Ò -Á-iÁ £ÒÍ® (B) V-Ái-Á £ÒÍ®
(C) ÷|º ÁiÁ £ÒÍ® (D) U-Ái-Á £ÒÍ®
Name of the groove in drill is :

(a) Flute (b) V-type groove

(c) Straight type groove (d) U-type groove

4. E¸-Á-ø©U-S® C¯¢-v-µz-vÀ ö\´-²® ÷Áø» :
(A) CøÇz-uÀ (B) Pøh-\À
(C) ©øµ-°-k-uÀ (D) xøÍ-°-k-uÀ
The operation mainly done on a shaping machine is :

(a) Machining a flat surface (b) Turning

(c) Thread cutting (d) Drilling

3 8376

5. ~qU-P-©õÚ Aøµ¨-¦aö\¯À ‰»® ö£Ó¨-£-k® xÀ-¼-¯® :
(A) 0.00125 ª.«. (B) 0.000025 ª.«. (C) 0.00625 ª.«. (D) 0.0025 ª.«.
The accuracy obtained by precision grinding is :

(a) 0.00125 mm (b) 0.000025 mm (c) 0.00625 mm (d) 0.0025 mm

6. G»õì-iU Aøµ¨-¦a \U-P-µ® ö\´-¯¨ £¯ß-£-k® ¤i-©õ-Ú¨ ö£õ-¸Ò :
(A) AµU-S (B) Âm-›-ø£-k (C) öµ]-Úõ´k (D) ]¼U-÷Pm
Bond used for making elastic grinding wheel is :

(a) Shellac (b) Vitrified (c) Resinoid (d) Silicate

7. ªÀ-¼[ C¯¢-v-µz-vÀ öÁm-kU-P-¸-Â-PÒ ö£õ-¸z-u¨-£-k® £õ-P® :
(A) Ea-]U-øP (B) ys £õ-P®
(C) _ÇÀ-usk (D) £o-÷©-øh
In a milling machine, cutters are mounted on :

(a) Overhanging arm (b) Column

(c) Arbor (d) Table

8. Bs-kUS J¸ •øÓ ö\´-²® £µõ-©-›¨¦ :
(A) C¯¢-v-µ® ö\¯-»Ø-Ö¨ ÷£õÚ ÷£õx ÷©Ø-öPõÒ-Ю £µõ-©-›¨-¦
(B) ÁÇU-P¨ £µõ-©-›¨-¦
(C) ö£¸®-£-Êx £õº¨¦ (A) v¸zv Aø©U-S® ÷Áø»
(D) uk¨¦ £µõ-©-›¨-¦
Maintenance done once in a year is known as __________.

(a) Breakdown Maintenance

(b) Routine Maintenance

(c) Capital Repairs or Corrective Maintenance

(d) Preventive Maintenance

[ v¸¨¦P / Turn over

8376 4

9. ì÷£-Ú-øµU Ps-k-¤-iz-u-Áº ¯õº ?
(A) ÷á®ì |õì-ªz (B) öíßÔ ©õmì-÷»
(C) G¼-öÁmÛ (D) \õ-»-©ß ö©º-›U
Who invented Spanner ?

(a) James Nasmith (b) Henry Maudslay

(c) Eli Whitney (d) Solymen Merrick

10. E¸-Q-¯ {ø» öÁÀ-i[ Gß-£x :
(A) ªß-uøh öÁÀ-i[ (B) AÊzu öÁÀ-i[
(C) öuº-ªm öÁÀ-i[ (D) AÊz-u-ªÀ-»õ öÁÀ-i[
Fusion Welding is :

(a) Resistance Welding (b) Pressure Welding

(c) Thermit Welding (d) Non-Pressure Welding

11. J¸ Gß.]. Aø©¨-¤À C¯U-Pz-vmh SÔ¨-¦P
- Ò __________ BP öPõ-kU-P¨-£k
- Q
- ß-ÓÚ.
(A) SÔ-±-k-PÒ (B) uP-ÁÀ-PÒ
(C) ©øµ SÔ-±-hõU-P® (D) Gs-q¸ uµ-Ä-PÒ
In NC System the program instructions are given as :

(a) Symbols (b) Information

(c) Thread Symbols (d) Numerical data

12. "©Û-u C¯¢-v-µz-vß ‰øÍ' GßÖ AøÇU-P¨-£-k® £õ-Pz-vß ö£¯º :
(A) ¤ì-hß (B) En-› (C) £Ø-\U-P-µ[-PÒ (D) Pm-k¨-£-kz-v
The brain of the Robot is called __________.

(a) Piston (b) Sensor (c) Gears (d) Controller

5 8376

13. uõ-Û-¯[-Q-°-¯-¼ß u¢-øu :
(A) I\U A]-÷©õÆ (B) áõºä öhÁÀ
(C) ÷á®ì Bº-Úõm (D) {U-÷Põ-»õ öhì-»õ
Father of Automation is :
(a) Isaac Asimov (b) George Devol
(c) James Arnot (d) Nikola Tesla

14. £o B´Ä Gß-£x :
(A) •øÓ B´-Ä (B) öuõ-ÈØ-\õø» Ch-Á-ø©-Ä
(C) £o AÍz-uÀ (D) EØ-£z-vø¯ ö£¸U-S-Á-x
Work study is :
(a) a method study (b) plant layout
(c) a work measurement (d) a technique of increasing production

15. ""ö£õx ©Ø-Ö® öuõ-ÈØ-\õø» ÷©»õsø©'' GßÓ ¦z-u-Pzøu GÊ-v-¯-Áº :
(A) F.W. öh´-»º (B) ø©U-÷PÀ L£õ-µ-÷h
(C) ¤¯º öÁº-Û-¯º (D) öíßÔ L÷£-¯õÀ
The book “General and Industrial Management” was written by :
(a) F.W. Taylor (b) Michael Faraday
(c) Pierre Vernier (d) Henry Fayol

£Sv & II / PART - II

SÔ¨¦ : H÷uÝ® £z- x Â- Ú õU- P - Ð US Âøh¯- Î U- P - Ä ®. ÂÚõ Gs 28 &US
Pmhõ¯©õP Âøh-¯-ÎUP-Ä®. 10x3=30
Note : Answer any ten questions. Question No. 28 is Compulsory.

16. Pøh-\À C¯¢-v-µz-vÀ ©øµ-¯-ÖU-S® `z-v-µz-vøÚ GÊ-x-P.
Mention the formula for cutting a thread in a lathe.

17. xøÍ-°-k® C¯¢-v-µz-vß ÁøP-PÒ H÷u-Ý® |õß-Q-øÚU SÔ¨-¤-kP.
Mention any four types of drilling machine.

[ v¸¨¦P / Turn over

8376 6

18. ""xøÍ-°-k-uÀ'' & Áøµ-¯-ÖU-P-Ä®.
Define “Drilling”.

19. ""Q÷Í-]['' Gß-ÓõÀ GßÚ ?
What is meant by “Glazing” ?

20. C¯Ø-øP-°À QøhU-S® Pi-Ú Aøµ¨¦ yÒ-P-Îß ö£¯º-PÒ ¯õøÁ ?
List out the Natural Abrasives.

21. Ai¨-£øh ªÀ-¼[ •øÓ-PøÍ SÔ¨-¤-kP.
Name the fundamental Milling process.

22. Aøµ¨¦ \U-P-µz-vß ""uµ®'' Gß-ÓõÀ GßÚ ?
What is meant by “Grade” of the grinding wheel ?

23. ÷|µi |m-h® Gß-ÓõÀ GßÚ ?
What is meant by Direct losses ?

24. C¯¢-vµ Pm-k¨-£õmk A»-Qß ÁøP-PÒ ¯õøÁ ?
What are the types of machine control unit ?

25. Qµõ[U ©Ø-Ö® ]»õm-hm ¼[U C¯¢-vµ ~m-£z-vß £¯ß ¯õx ?
What is the use of crank and slotted link mechanism ?

26. ""uõ-Û-¯[-Q-°-¯À'' Gß-ÓõÀ GßÚ ?
What is meant by “Automation” ?

27. ""E¸-Á-ø©z-uÀ'' & Áøµ-¯-ÖU-P-Ä®.
Define “Shaping”.

28. CNC C¯¢-v-µz-vß {øÓ-PÒ ‰ß-ÔøÚ GÊ-xP.
Write any three advantages of CNC machine.

7 8376

£Sv & III / PART - III

SÔ¨¦ : GøÁ÷¯Ý® I¢-x Â-ÚõU-P-ÐUS Âøh¯-ÎU-P-Ä®. ÂÚõ Gs 35 &US
Pmhõ¯©õP Âøh-¯-ÎUP-Ä®. 5x5=25

Note : Answer any five questions. Question No. 35 is Compulsory.

29. xøÍ-°-k® C¯¢-v-µz-vß AÍøÁ GÆ-ÁõÖ SÔ¨-¤-k-Áõ´ ?
How is the size of a drilling machine specified ?

30. E¸-Á-ø©U-S® C¯¢-v-µz-vß ÁøP-P-øÍ Á›-ø\¨-£-kz-xP.
List out the types of shaping machines.

31. ""Aøµ¨-¦a \U-P-µzøu JÊ[S £kz-x-uÀ'' £ØÔ £hz-x-hß ÂÍU-SP.
Explain “Truing of a grinding wheel” with a diagram.

32. ""ÁøÍ-¯z-uõÀ E¯-Â-hÀ'' £h® Áøµ¢x ÂÍU-SP.
Explain “Ring Lubrication” with a diagram.

33. BU]A]m-i-¼ß Pm-i[ & £h® Áøµ¢x ÂÍU-SP.
Explain the Oxy-Acetylene cutting with diagram.

34. C¯¢-v-µU Pm-k¨-£õmk A»-Qß ÁøP-P-ÎÀ H÷u-Ý® Jß-ÔøÚ £h® Áøµ¢x
ÂÍU-SP.
Explain with neat sketch any one type of machine control unit.

35. ©Ûu C¯¢-v-µz-vß ÁøP-PÒ £ØÔ GÊ-xP.
Write about the types of robots.

[ v¸¨¦P / Turn over

8376 8

£Sv & IV / PART - IV

SÔ¨¦ : A-øÚz-x ÂÚõUPÐUS® Âøh¯-ÎU-P-Ä®. 2x10=20
Note : Answer all the questions.

36. (A) Pøh- \ À C¯¢- v - µ z- v À ö\´- ¯ ¨- £ - k ® ÷Áø»- P Ò H÷u- Ý ® Cµs- i øÚ
£hz-x-hß ÂÍU-SP.
AÀ»x
(B) ªÀ-¼[ öÁm-kU-P-¸-Â-ø¯¨ ¤iU-S® \õ-u-Ú[-PÒ GøÁ-÷¯-Ý® Cµs-iøÚ
£hz-x-hß ÂÍU-SP.
(a) Explain any two operations performed in lathe with neat sketch.
OR
(b) Explain any two cutter holding devices with diagram.

37. (A) ÷Pì öÁÀ-i[ & £h® Áøµ¢x ÂÍU-SP.
AÀ»x
(B) EØ-£z-vz vÓ-øÚ Av-P-›U-S® ÁÈ-•-øÓ-PøÍ ÂÁ-›U-P-Ä®.
(a) Explain Gas welding with a neat sketch.
OR
(b) What are the factors for increasing Productivity ?

-o0o-

Study Materials
Notes

Model Papers Class 6 Notes

Sample Papers Class 7 Notes
Half Yearly Sample Papers Class 8 Notes

Class 9 Notes
Important Resources
Class 10 Notes
Periodic Table
Class 11 Notes
Writing Skills / Formats

Maps of India / World Class 12 Notes

Books and Solutions

NCERT Books
NCERT Book Solutions
HC Verma Chapter Wise Solutions
RD Sharma Solutions
CGBSE Solutions