CBSE Class 12 Marking Scheme 2021 for Engineering Graphics

Class: XII
Session: 2020-21
ENGINEERING GRAPHICS(046)
Sample Question Paper (Theory)
Marking Scheme
Time Allowed: 3 Hours Maximum Marks: 70

Distribution of Marks
1. Answer the following Multiple-Choice questions. Print the correct choice Marks
on your drawing sheet.
(i) (b) Perspective projection. 1
(ii) (c) Knuckle thread 1
(iii) (a) 1.5 d 1
(iv) (d) Gun Metal 1
(v) (a) Square rods 1
2. (i) ISOMETRIC SCALE 4
Marking of main divisions of 10 mm (at least seven divisions) 11/2
with smaller divisions of 1 mm in first part, on true length.
Projections from scale 1:1 to get points on isometric scale, to 11/2
get isometric length.
Printing ‘True Length/Scale 1:1’, ‘Isometric Length/ Isometric 1
Scale’ and marking angles of 30 o & 45o.

(ii) ISOMETRIC PROJECTION OF A PENTAGONAL PRISM 8
Drawing helping figure. 1
Drawing both the isometric pentagons. 3
Drawing the four face edges. 2
Marking the axis (1/2) and direction of viewing (1/2). 1
Dimensions. 1

(iii) ISOMETRIC PROJECTION OF A HEMISPHERE, PLACED 12
CENTRALLY, ON THE TOP RECTANGULAR SURFACE OF A
TRIANGULAR PRISM

TRIANGULAR PRISM 6
Drawing helping figure. 1
Drawing both the isometric triangles. 2
Drawing the three horizontal edges. 11/2
Dimension and axis. 11/2

HEMISPHERE 6
Drawing ellipse with centre lines. 21/2
Drawing curved surface. 11/2
Indicating the direction of viewing and axis. 1
Dimensions. 1

1

3. (i) SQUARE THREAD PROFILE 8

Horizontal and vertical distances (equal to half of pitch), 2
marked correctly.
Drawing crests (1), roots (1) of threads (minimum two) and 3
flanks (1), drawn correctly.
Drawing hatching lines and conventional break. 1
Standard dimensions. 2

[ OR ]

HEXAGONAL HEADED BOLT 8

Drawing head of the bolt. 3
Drawing shank of the bolt with threaded portion. 2
Drawing side view. 1
Standard dimensions. 2

(ii) 600 CSK HEAD RIVET 5

Front view with vertical axis. 21/2
Top view. 11/2
Standard dimensions. 1

[ OR ]

STUD WITH SQUARE NECK 5

Front view with horizontal axis. 21/2
Side view. 11/2
Standard dimensions. 1

4. TURNBUCKLE (Assembly)

(a) FRONT VIEW UPPER HALF IN SECTION: 15
Drawing the upper half of body (4) with hatching lines (1). 5
Drawing the lower half of body. 4
Drawing both the rods with 50 mm insertion in the body and 6
conventional ends.

(b) SIDE VIEW: 7
Drawing two circles of body. 2
Drawing conventional end of rod with threading. 21/2
Drawing both supporting plates at a distance of 32 mm. 2
1
Drawing cutting plane. /2

DETAILS : 6
Printing title. 1
Scale used. 1
Projection symbol. 1
2

Six important dimensions. 3

[OR]

SLEEVE AND COTTER JOINT (Dis assembly)

(i) SLEEVE
(a) SECTIONAL FRONT VIEW : 8
Drawing the boundary of sleeve with internal hole of dia 4
30mm.
Drawing cotter holes. 2
Hatching lines 2

(b) LEFT SIDE VIEW : 4
Drawing both circles. 2
Drawing hidden lines of cotter. 1
Cutting plane. 1

(ii) COTTER B
(a) FRONT VIEW: 5
Drawing cotter with taper on one side. 3
Drawing curves on both ends. 2

(b) TOP VIEW : 5
Drawing boundary of cotter with hidden line. 3
Drawing both curves. 2

DETAILS : 6
Printing titles. 1
Scale used. 1
Projection symbol. 1
Six important dimensions. 3

3

2(a)

2(b)

4

2(c)

3(a)

5

OR

3 (b).

6

OR

7

4.

Figure 1

OR

8

Figure 2

9