56 Machine Drawing
dharm
d:\N-Design\Des3-1.pm5 Seventh Print
THEORY QUESTIONS
3.1 What are the elements to be considered while obtaining a projection and what is an orthographic
projection?
3.2 When is a projection of an object called an orthographic projection?
3.3 Explain the following, indicating the symbol to be used in each case:
(a) First angle projection, (b) Third angle projection
3.4 List-out the six possible orthographic projections that may be obtained for an object in space,
specifying their relative positions.
3.5 What is a one-view drawing? For what type of objects these can be used?
3.6 What is the basis on which the number of views required for an object is selected?
3.7 What are the points to be considered while laying-out the different views of an object?DRAWING EXERCISES
3.1 Draw (i) the view from the front and (ii) the view from right of the object shown in Fig. 3.23.
3.2 Draw (i) the view from the front, (ii) the view from above and (iii) the view from the right, of the
objects shown in Figs. 3.24, 3.27, 3.28, 3.31 and 3.38.
3.3 Draw (i) the view from the front and (ii) the view from above of the objects shown in Figs. 3.25,
3.32, 3.34, 3.36 and 3.37.
3.4 Draw (i) the view from the front, (ii) the view from above and (iii) the view from the left of the
objects shown in Figs. 3.26, 3.29, 3.30, 3.33 and 3.35.20
10
40
20
20
10
(^203030)
60
30
20
20
20
25
100
(^4025)
40
20
25
30
30 12 65
12
10
75
Fig. 3.23 Fig. 3.24