51) Is it essential to show all the hidden lines in dotted in a assembly drawing ?

Generally hidden lines are omitted from the sectional view and not essential to show all hidden lines in assembly drawing. If it is necessary to show more clearly a hidden part in the section or aiding in dimensioning the view, they may be drawn.

52) How are thin materials shown in sectional drawing ?

Thin materials such as sheets, gaskets and electrical sections are shown solid in section and adjoining parts should be separated by a small space.

53) What is meant by development ?

Development is the drawing of all the surfaces of an object on a plane to make a pattern. If it is folded or rolled it will form the required object. The main applications are in sheet metal work,sheet plastic fabrication and many other industrial applications.

54) What are the method of development ?

1.Parallel Line Development: It is used for patterns of prisms and cylinders.
2.Radial Line Development: This is used for surfaces of regular tapering forms such as pyramids and corns.
3.Triangulation Development: It is used when the connecting surface is neither prismatic nor pyramidal such as developing warped and double curved surfaces.

55) What are the production drawings ?

Production drawings are the drawings which are required for the fabrication of any product.

56) What is meant by assembly drawings ?

Drawing which shows how two or parts are assembled and identifies all the pieces which form the assembly is called assembly drawings.

57) What do you mean by detail drawing ?

It shows the essential shape, size and specifications required for the construction of each unit of a product.

58) What are the different types of detail drawings ?

1) Pattern detail drawings
2) Stamping detail drawings
3) Casting detail drawings
4) Welding detail drawings
5) Forging detail drawings

59) Why is a pictorial drawing shaded ?

To make the appearance of a pictorial drawing more natural .

60) What is meant by interpenetration of solids ?

If one solid penetrates into the other solid of the same or different cross section then surfaces of the both solids come in contact and outline of the penetrating solid can be seen which is called interpenetration of solid.