CBSE Class-12^th ENGINEERING GRAPHICS Outside Delhi Set-4 2017

General Instructions:

1. Attempt all the questions.
2. Use both sides of the drawing sheet, if necessary.
3. All dimensions are in millimeters.
4. Missing and mismatching dimensions, if any, may be suitably assumed.
5. Follow the SP: 46-2003 revised codes (with first angle method of projection).
6. In no view of question 2, hidden edges or lines are required.
7. In question 4, hidden edges or lines are to be shown in views without section.
8. Give your answers according to questions.
9. Answer the following Multiple Choice Questions. Print the correct choice on your drawing sheet:
10. The dimension lines are drawn as?
11. Small dash lines (b) Chain lines (c) Wavy lines (d) Thin continuous lines
12. The figure given below shows the conventional representation of which threads?

1. External square threads (b) External V-threads (c) Internal square threads (d) Internal V-threads
2. Why Gib head is provided on a Gib head key?
3. To facilitate the withdrawal of the key without disturbing the setting of the Hub.
4. For lubrication purpose
5. For the aesthetic sense
6. To reduce the cost of manufacture
7. What is the purpose of an Open bearing?
8. To join two pipes (b) To support the moving shaft (c) To join two shafts (d) To

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support the pipes

1. Solid cast iron pulley is attached to the shaft by means of a _____.

(a) Rivet (b) Bolt (c) Key (d) Stud

Ans. (i) (d) or Thin Continuous Lines.

1. (a) or External square threads.
2. (a) or To facilitate the withdrawal of the key without disturbing the setting of the Hub.
3. (b) or To support the moving shaft.
4. (c) or Key.

2. (i) Construct an isometric scale.

Ans. Marking of divisions of 10 mm, including division of first part of 1 mm on true length.

1. Projections from scale 1:1 to get points on isometric scale, construction of isometric scale.
2. Printing ‘True Length/Scale 1:1’, ‘Isometric Length/Isometric Scale’ and marking angles of 30°&40°.

1. A frustum of triangular pyramid (base edge 40 mm, top edge 30 mm and height 60
2. is kept with its axis perpendicular to H.P. One of the base edges is nearer to the

observer and is parallel to V.P. Draw its isometric projection. Show the axis and indicate the direction of viewing. Give all dimensions.

Ans. ISOMETRIC PROJECTION OF A FRUSTUM OF A TRIANGULAR PYRAMID

1. Drawing helping figure of both triangles.
2. Drawing isometric triangle, on top and at the base.
3. Drawing three slant edges.
4. Marking the vertical axis (½) and direction of viewing (½).
5. Dimensions.

1. A vertical hexagonal prism (base edge 20 mm, height 70 mm) is placed centrally on

the top circular face of a hemisphere (Diameter 80 mm). Two base edges of the prism are perpendicular to V.P. The common axis is perpendicular to H.P. Draw the isometric projection of the combination of solids. Show the common axis and indicate the direction of viewing. Give all dimensions.

Ans. ISOMETRIC PROJECTION OF A HEXAGONAL PRISM PLACED, CENTRALLY, ON A HEMISPHERE

HEMISPHERE

1. Drawing isometric ellipse (2 <math>\frac{1}{2}</math>) along with centre lines (<math>\frac{1}{2}</math>).
2. Drawing semicircular portion of hemisphere.

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