CBSE Class 12 Question Paper 2023 Solution Engineering Graphics

e s t i o n P a p er
Qu
Solu t i o n
2023

Marking Scheme
Strictly Confidential
(For Internal and Restricted use only)
Senior School Certificate Examination, 2023
SUBJECT NAME – ENGINEERING GRAPHICS (SUBJECT CODE 046) (PAPER CODE 68)

General Instructions: -
1 You are aware that evaluation is the most important process in the actual and correct
assessment of the candidates. A small mistake in evaluation may lead to serious problems
which may affect the future of the candidates, education system and teaching profession.
To avoid mistakes, it is requested that before starting evaluation, you must read and
understand the spot evaluation guidelines carefully.
2 “Evaluation policy is a confidential policy as it is related to the confidentiality of the
examinations conducted, Evaluation done and several other aspects. Its’ leakage to
public in any manner could lead to derailment of the examination system and affect
the life and future of millions of candidates. Sharing this policy/document to
anyone, publishing in any magazine and printing in News Paper/Website etc may
invite action under various rules of the Board and IPC.”
3 Evaluation is to be done as per instructions provided in the Marking Scheme. It should not
be done according to one’s own interpretation or any other consideration. Marking
Scheme should be strictly adhered to and religiously followed. However, while
evaluating, answers which are based on latest information or knowledge and/or are
innovative, they may be assessed for their correctness otherwise and due marks be
awarded to them. In class-X, while evaluating two competency-based questions,
please try to understand given answer and even if reply is not from marking scheme
but correct competency is enumerated by the candidate, due marks should be
awarded.
4 The Marking scheme carries only suggested value points for the answers
These are in the nature of Guidelines only and do not constitute the complete answer. The
students can have their own expression and if the expression is correct, the due marks
should be awarded accordingly.
5 The Head-Examiner must go through the first five answer books evaluated by each
evaluator on the first day, to ensure that evaluation has been carried out as per the
instructions given in the Marking Scheme. If there is any variation, the same should be
zero after deliberation and discussion. The remaining answer books meant for evaluation
shall be given only after ensuring that there is no significant variation in the marking of
individual evaluators.
6 Evaluators will mark( √ ) wherever answer is correct. For wrong answer CROSS ‘X” be
marked. Evaluators will not put right (✓)while evaluating which gives an impression that
answer is correct and no marks are awarded. This is most common mistake which
evaluators are committing.
7 If a question has parts, please award marks on the right-hand side for each part. Marks
awarded for different parts of the question should then be totaled up and written in the left-
hand margin and encircled. This may be followed strictly.
8 If a question does not have any parts, marks must be awarded in the left-hand margin and
encircled. This may also be followed strictly.
9 If a student has attempted an extra question, answer of the question deserving more
marks should be retained and the other answer scored out with a note “Extra Question”.

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10 No marks to be deducted for the cumulative effect of an error. It should be penalized only
once.
11 A full scale of marks 70 has to be used. Please do not hesitate to award full marks if the
answer deserves it.
12 Every examiner has to necessarily do evaluation work for full working hours i.e., 8 hours
every day and evaluate 20 answer books per day in main subjects and 25 answer books
per day in other subjects (Details are given in Spot Guidelines).This is in view of the
reduced syllabus and number of questions in question paper.
13 Ensure that you do not make the following common types of errors committed by the
Examiner in the past:-
● Leaving answer or part thereof unassessed in an answer book.
● Giving more marks for an answer than assigned to it.
● Wrong totaling of marks awarded on an answer.
● Wrong transfer of marks from the inside pages of the answer book to the title page.
● Wrong question wise totaling on the title page.
● Wrong totaling of marks of the two columns on the title page.
● Wrong grand total.
● Marks in words and figures not tallying/not same.
● Wrong transfer of marks from the answer book to online award list.
● Answers marked as correct, but marks not awarded. (Ensure that the right tick mark
is correctly and clearly indicated. It should merely be a line. Same is with the X for
incorrect answer.)
● Half or a part of answer marked correct and the rest as wrong, but no marks awarded.
14 While evaluating the answer books if the answer is found to be totally incorrect, it should
be marked as cross (X) and awarded zero (0)Marks.
15 Any un assessed portion, non-carrying over of marks to the title page, or totaling error
detected by the candidate shall damage the prestige of all the personnel engaged in the
evaluation work as also of the Board. Hence, in order to uphold the prestige of all
concerned, it is again reiterated that the instructions be followed meticulously and
judiciously.
16 The Examiners should acquaint themselves with the guidelines given in the “Guidelines
for spot Evaluation” before starting the actual evaluation.
17 Every Examiner shall also ensure that all the answers are evaluated, marks carried over to
the title page, correctly totaled and written in figures and words.
18 The candidates are entitled to obtain photocopy of the Answer Book on request on
payment of the prescribed processing fee. All Examiners/Additional Head Examiners/Head
Examiners are once again reminded that they must ensure that evaluation is carried out
strictly as per value points for each answer as given in the Marking Scheme.

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General Note:

a) Marks are to be awarded in proportion to the work done.
b) Mistakes in dimensioning up to ± 1.0 mm may be ignored.
c) In dimensioning, arrow-heads of various types, as per SP: 46-2003 codes are acceptable.
However, where space is too small for an arrowhead, oblique stroke or dot may be
employed.
d) In question no. 21 and in sectioned view of question no. 23, if hidden edges / lines are
drawn, no marks should be deducted.
e) Other standard methods of drawing / proportions for isometric scale, nuts, heads of bolts,
screws etc. employed by examinees, may also be accepted.
f) The answers/solutions must be evaluated adhering to marking scheme and no marks
should be deducted without mistake.

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Set 4 M.S.>Code P06846
$

MARKING SCHEME
ENGINEERING GRAPHICS

SECTION – A 201=20

1. (c) a single scale

2. (c) the front view

3. (d) guide lines

4. (a) a triangle

5. (b) a cylinder on a cube

6. (b) Bush bearing

7. (d) to aid tightening and loosening of rods by tommy bar

8. (a) 5mm.

9. (d) Both (b) and (c).

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10. (c) Nine

11. (c) (i) and (iv) only

12. (a) (iii) only

13. (c) common axis is vertical

14. (c) The solid is resting on its apex when its axis is || to VP.

15. (a) Both (A) and (R) are true and (R) is the correct explanation of (A).

16. (c) in Steel structures

17. (b) non-threaded fastener

18. (c) 2d

19. (d)

20. (a)

SECTION – B

21. (a) ISOMETRIC SCALE 5
(i) Drawing lines at an angle of 300 and 450. 1
(ii) Marking of divisions of 10 mm, including division of first part of
1 mm on true length 1
(iii) Projections from scale 1 : 1 to get points on isometric scale,
construction of isometric scale 2
(iv) Printing “True length/Scale 1 : 1”,
“Isometric length/Isometric scale” and marking 30˚, 45˚ 1

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(b) ISOMETRIC PROJECTION OF INVERTED PENTAGONAL
PYRAMID 10
(i) Drawing helping figure of pentagon 2
(ii) Drawing isometric pentagon keeping one base edge
perpendicular to V.P. 3
(iii) Drawing slant edges 3
(iv) Marking the axis (½) and direction of viewing (½) 1
(v) Dimensions 1
NOTE: For incorrect position, 1 mark should be deducted.

22. METRIC THREAD (EXTERNAL) 8
(i) Horizontal distances (equal to half of pitch), vertical distances
(D=0.866P, D/8 and D/6) marked correctly 2
(ii) Drawing of crests (1) and roots (1) of threads (minimum two),
flanks (1), drawn correctly 3
(iii) Drawing hatching lines with conventional break 1
(iv) Standard dimensions 2

OR

HEXAGONAL NUT (with axis vertical) 8
(i) Front view (Across Corner or Across Flat) drawn correctly 3
(ii) Top view drawn correctly 3
(iii) Standard dimensions 2

NOTE: For incorrect position or if sketched freehand, 2 marks
should be deducted, in all.

23. FLANGE PIPE JOINT (ASSEMBLY)
(i) Front view lower half in section 13
- Drawing boundary of both flange pipes in upper half portion
(2), fillets of R6 (½), four vertical lines (½) and conventional
ends of pipes (½). 3½

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- Drawing boundary of both flange pipes in lower half portion
(2), fillets of R6 (½), horizontal lines of inner wall of pipes of
Ø70 (½) and conventional ends of pipes (½). 3½
- Drawing the hatching lines in lower half portion of both flange
pipes. 2
- Drawing bolts and nuts of Ø12 correctly (At least in section
portion) on PCD of Ø136. 3
- Drawing gasket in lower half with shading/cross hatching and
gasket in upper half. 1
(ii) Right side view 8
- Drawing six circles, including hidden circle of Ø102 (½) and
pitch circle of Ø136 (½). 5
- Drawing hatching lines to indicate pipe thickness. 1
- Drawing Square, Chamfer Circle, Circle of Ø12 and broken
circle of Ø0.8d for nuts and bolts on PCD Ø136 (At least in
correspondence with front view). 1½
- Drawing cutting plane. ½
DETAILS 6
Printing titles (1), scale used (1), drawing projection symbol (1)
and six important dimensions (3).

OR

SLEEVE AND COTTER JOINT (DISASSEMBLY)
(a) SLEEVE
(i) Full sectional front view 8
- Drawing the boundary of sleeve with rounds of R4 (2½) and
lines showing hole of Ø28 (1). 3½
- Drawing the cotter holes with taper (2), showing correctness of
taper in cotter holes (½) as per question. 2½
- Drawing hatching lines. 2

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(ii) Top view 6
- Drawing the boundary of sleeve with rounds of R4 (2½) and
hidden lines showing hole of Ø28 (1). 3½
- Drawing both cotter holes with vertical lines. 2 2
- Drawing cutting plane ½
(b) ROD A
(i) Front view upper half in section 4
- Drawing the rod with chamfered end (4x45˚) and conventional
end. 2
- Drawing cotter hole with taper, in upper half. 1
- Drawing hatching lines in upper half. 1
(ii) Left side view 3
- Drawing two circles. 1½
- Drawing hatching lines in inner circle showing broken end of
rod. ½
- Drawing hidden lines for cotter hole. ½
- Drawing cutting plane ½
DETAILS 6
Printing titles (1), scale used (1), drawing projection symbol (1),
six important dimensions (3).

NOTE: Assumed dimensions used for cotter’s thickness may be
considered due to misprint.

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