CBSE Class 12 Engineering Graphics Question Paper 2019 Solutions

SSCE Marking Scheme 2019 Code no. – 68
Strictly Confidential: (For Internal and Restricted use only)

MARKING SCHEME
Senior School Certificate Examination – 2019
Subject : ENGINEERING GRAPHICS
Sub Code : 046
Paper Code : 68
ALL QUESTIONS ARE TO BE ANSWERED CORRECTLY AND ACCURATELY.

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.
Evaluation is a 10-12 days mission for all of us.
Hence, it is necessary that you put in your best
efforts in this process.
2. 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 marks be awarded to them.
3. 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.
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.
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SSCE Marking Scheme 2019 Code no. – 68

4. 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.
5. If a question does not have any parts, marks must be
awarded in the left hand margin and encircled.
6. If a student has attempted an extra question, answer
of the question deserving more marks should be
retained and the other answer scored out.
7. No marks to be deducted for the cumulative effect of
an error. It should be penalized only once.
8. A full scale of marks 0-70 has tobe used. Please do
not hesitate to award full marks if the answer
deserves it.
9. Every examiner has to necessarily do evaluation work
for full working hours i.e. 8 hours every day and
evaluate 25 answer books per day.
10. Ensure that you do not make the following common
types of errors committed by the Examiner in the
past:-
 Leaving answer or part thereof un-assessed in an
answer book.
 Giving more marks for an answer than assigned
to it.
 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.
 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

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SSCE Marking Scheme 2019 Code no. – 68

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.
11. While evaluating the answer books if the answer is
found to be totally incorrect, it should be marked as
(X) and awarded zero (0) Marks.
12. Any un-assessed portion, non-carrying over of marks
to the title page, or totalling 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.
13. The Examiners should acquaint themselves with the
guidelines given in the Guidelines for spot Evaluation
before starting the actual evaluation.
14. Every Examiner shall also ensure that all the answers
are evaluated, marks carried over to the title page,
correctly totalled and written in figures and words.
15. The Board permits candidates to obtain photocopy of
the Answer Book on request in an RTI application and
also separately as a part of the re-evaluation process
on payment of the processing charges.

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. 2 and in sectioned view of question no. 4, if
hidden edges / lines are drawn, no marks should be deducted.
e) Other standard methods of drawing / proportions for features
like 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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Subject : ENGINEERING GRAPHICS
Sub Code : 046
Paper Code : 68

VALUE POINTS
Distribution
of Marks
1. MULTIPLE CHOICE QUESTIONS 5
(i) (b) or Isometric projection. 1
(ii) (a) or Bolt and nut. 1
(iii) (a) or Passes through a hole in one part only. 1
(iv) (d) or Better stability on the surface. 1
(v) (c) or 3. 1

2. (i) ISOMETRIC SCALE 4
(i) Marking of divisions of 10 mm, including division of 1
first part of 1 mm on true length.
(ii) Projections from scale 1:1 to get points on isometric 2
scale, construction of isometric scale.
(iii) Printing ‘True Length/Scale 1:1’, ‘Isometric 1
Length/Isometric Scale’ and marking angles of 30 o
& 45o.

(ii) ISOMETRIC PROJECTION OF FRUSTUM OF AN 7
INVERTED PENTAGONAL PYRAMID
(i) Drawing helping figures of pentagons. 11/2
(ii) Drawing isometric pentagons keeping one base edge 21/2
parallel to V.P. and nearer to observer.
(iii) Drawing slant edges. 1
(iv) Marking the axis ( /2) and direction of viewing ( /2).
1 1 1
(v) Dimensions. 1

NOTE: For incorrect position, 1 mark should be deducted.

(iii) ISOMETRIC PROJECTION OF A CYLINDER, PLACED 13
CENTRALLY, ON THE TOP RECTANGULAR FACE OF A
TRIANGULAR PRISM
TRIANGULAR PRISM 7
(i) Drawing helping figure. 1
(ii) Drawing both isometric triangles. 21/2
(iii) Drawing long edges. 11/2
(iv) Marking the axis (1/2) and direction of viewing (1/2). 1
(v) Dimensions. 1

CYLINDER 6
(i) Locating the centre on the top rectangular face of 1
the prism.
(ii) Drawing the ellipses (2) and generators (1). 3
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SSCE Marking Scheme 2019 Code no. – 68

(iii) Marking the vertical axis (1/2) and centre lines of 1
ellipse (1/2).
(iv) Dimensions. 1

NOTE: For incorrectly placed solids, deductions, as proposed in (ii) above,
should be used.

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

HEXAGONAL HEADED BOLT (with axis horizontal) 8
(a) FRONT VIEW (A/F or A/C):
(i) Drawing head of the bolt. 2
(ii) Drawing the threaded (1) and unthreaded (1) portion 2
of the shank.
(b) SIDE VIEW :
(i) Drawing hexagon. 1
(ii) Drawing chamfering circle (1/2) and two circles 1
showing threads as per convention (1/2).
(c) Standard dimensions. 2
NOTE: 2 marks should be deducted, in all, if sketched freehand, instead
of drawing to scale 1:1.

(ii) STUD WITH SQUARE NECK 5
(i) Front view with vertical axis. 21/2
(ii) Top view. 11/2
(iii) Standard dimensions. 1
[OR]

SOCKET HEAD MACHINE SCREW (Front View) 5

(i) Drawing the head. 2
(ii) Drawing shank with axis horizontal 2
(iii) Standard dimensions. 1
NOTE: 1 mark should be deducted, in all, if these components are
drawn with instruments, instead of being sketched freehand.
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SSCE Marking Scheme 2019 Code no. – 68

4. GIB AND COTTER JOINT (Assembly)

(i) FRONT VIEW (Upper Half in Section) : 16
(a) Drawing upper half portion of strap and rod (4), 6
clearance between cotter and strap (1), clearance
between gib and rod (1).
(b) Drawing lower half portion of strap and rod. 4
(c) Drawing the cotter (2) and gib (2). 4
(d) Drawing the hatching lines in upper half portion of 2
strap and rod.

(ii) LEFT SIDE VIEW: 6
(a) Drawing outline of strap and rod. 2
(b) Drawing hatching lines in rod. 1
(c) Drawing cotter and gib with hidden lines. 21/2
(d) Drawing cutting plane. 1/2

DETAILS : 6
Printing title (1), scale used (1), drawing projection
symbol (1) and six dimensions (3).

[OR]

SOLID CAST IRON PULLEY (Dis-assembly)

(i) PULLEY
(a) FRONT VIEW (Upper Half in Section) : 8
(i) Drawing the upper half portion of pulley. 3
(ii) Drawing hole of Ø8 (1/2) and key way (1/2). 1
(iii) Hatching lines 1
(iv) Drawing the lower half portion of pulley. 3

(b) RIGHT SIDE VIEW : 8
(i) Drawing the 5 circles. 5
(ii) Drawing the shaft circle of Ø20 with keyway. 11/2
(iii) Drawing holes of Ø8 on Ø110 P.C.D. 1
(iv) Drawing cutting plane. 1/2

(ii) RECTANGULAR SUNK TAPER KEY 6
(a) FRONT VIEW drawn correctly 3
(b) LEFT SIDE VIEW drawn correctly 3

DETAILS : 6
Printing titles of both (1), scale used (1), drawing
projection symbol (1) and six dimensions (3).
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