CBSE Class-12 Exam 2017 : Marking Scheme, Engineering Graphics

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Class 12 papers

CBSE Class-12 Exam 2017 : Marking Scheme

Question Paper, Engineering Graphics

CBSE Class-12 Exam 2017 :  Engineering Graphics (Delhi)

Senior School Certificate Examination – 2017
Subject : ENGINEERING GRAPHICS

Sub Code : 046
Paper Code : 68/1
ALL QUESTIONS ARE TO BE ANSWERED CORRECTLY AND ACCURATELY.
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.
VALUE POINTS
Distribution
of Marks
Q 1. MULTIPLE CHOICE QUESTIONS 5
(i) (d) or Thin Continuous Lines. 1
(ii) (a) or External square threads. 1
(iii) (a) or To facilitate the withdrawal of the key without disturbing the setting of the Hub.1
(iv) (b) or To support the moving shaft. 1
(v) (c) or Key. 1
Q 2. (i) ISOMETRIC SCALE 4
(i) Marking of divisions of 10 mm, including division of first part of 1 mm on true length.1
(ii) Projections from scale 1:1 to get points on isometric scale,construction of isometric scale.2
(iii) Printing ‘True Length/Scale 1:1’, ‘Isometric Length/Isometric Scale’ and marking angles of 30 o & 45o.

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CBSE Class-12 Exam 2017 :  Engineering Graphics (Outside)

Senior School Certificate Examination – 2017
Subject : ENGINEERING GRAPHICS

Sub Code : 046
Paper Code : 68
ALL QUESTIONS ARE TO BE ANSWERED CORRECTLY AND ACCURATELY.
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.
VALUE POINTS
Distribution
of Marks
Q 1. MULTIPLE CHOICE QUESTIONS 5
(i) (b) or Orthographic Projection. 1
(ii) (b) or J. 1
(iii) (d) or 3d. 1
(iv) (c) or To hold the jaws of the fork from opening wide when the cotter is inserted. 1
(v) (d) or A combination of pulleys and belt. 1
Q 2. (i) ISOMETRIC SCALE 4
(i) Marking of divisions of 10 mm, including division of first part of 1 mm on true length. 1
(ii) Projections from scale 1:1 to get points on isometric scale, construction of isometric scale. 2
(iii) Printing ‘True Length/Scale 1:1’, ‘Isometric Length/Isometric Scale’ and marking angles of 30 o & 45o. 1

(ii) ISOMETRIC PROJECTION OF A FRUSTUM OF A INVERTED TRIANGULAR PYRAMID 7
(i) Drawing helping figure of both triangles. 11/2
(ii) Drawing isometric triangle, on top and at the base. 2
(iii) Drawing three slant edges. 11/2
(iv) Marking the vertical axis (1/2) and direction of viewing (1/2). 1
(v) Dimensions. 1

NOTE: For incorrect position, 1 mark should be deducted.
(iii) ISOMETRIC PROJECTION OF A PENTAGONAL PRISM PLACED, CENTRALLY, ON A HEMISPHERE13
HEMISPHERE 6
(i) Drawing isometric ellipse (21/2) along with centre lines (1/2). 3
(ii) Drawing semicircular portion of hemisphere. 11/2
(iii) Marking the vertical axis. 1/2
(iv) Dimensions. 1
PENTAGONAL PRISM 7
(i) Drawing helping figure. 1
(ii) Drawing both isometric pentagons. 2
(iii) Drawing vertical edges. 2
(iv) Marking the vertical axis (1/2) and direction of viewing (1/2). 1
(v) Dimensions. 1
NOTE: For incorrectly placed solids, deductions, as proposed in (ii) above, should be used.
Q 3. (i) KNUCKLE THREAD PROFILE 8
(i) Horizontal distances (equal to half of pitch), vertical distance(0.5P) marked correctly.2
(ii) Semicircular profile for crests and roots of threads (minimumtwo), drawn correctly.3
(iii) Drawing hatching lines. 1
(iv) Standard dimensions

Courtesy: CBSE