CBSE Class-12 Syllabus 2019-20 (Engineering Graphics)
The subject of 'Engineering Graphics' has become an indispensable tool for Engineers, Technocrats, Architects, Draftsmen, Surveyors, Designers and many other professionals in the recent times. Understanding of its fundamental principles and wider applications of the same in the above fields and many other daily life situations form the basis for the syllabus at Senior Secondary Stage.
The study of the subject of Engineering Graphics at Senior School Level aims at helping the learner to:
• develop clear concept and perception of form, proportion and application.
• develop the skill of expressing three-dimensional and two-dimensional objects into professional language and vice versa.
• acquire the ability to readily draw neat sketches, often needed in "On -job situations".
• develop a clear understanding of plane and solid Geometry and machine drawing so as to apply the same in relevant practical fields such as technology and industry.
• acquire speed and accuracy in use of drawing instruments.
• use technology (CAD) in developing isometric and orthographic projections of simple objects
One Paper: 3 Hours ; 70 Marks
Unit - I
|Isometric Projections of Solids
Unit - II
A. Drawing of Machine parts
B. Assembly Drawing and Dis-assembly drawings
2. Rod joints
3. Tie-rod and pipe joints
Unit I: Isometric Projection of Solids : 50 Periods
(i) Construction of isometric scale showing main divisions of 10mm and smaller divisions of1mm, also showing the leading angles. Drawing helping view/s such as triangles, pentagon, hexagon, etc., using isometric scale.
(ii) Isometric projection (drawn to isometric scale) of solids such as cube, regular prism and pyramids (triangular, square, pentagonal and hexagonal), cone, cylinder, sphere, hemi- sphere, frustum of right regular pyramids (triangular, square, pentagonal, hexagonal) and cone, when they are cut by a plane parallel to the base. The axis and the base side of the solid should be either perpendicular to HP / VP or parallel to HP and VP. (Indicate the direction of viewing)
(iii) Combination of two solids (except "frustum" of Pyramids and Cone) Keeping the base side parallel or perpendicular to HP/VP and placed centrally together, axis of both the solids should not be given parallel to HP.
Note: (1) Question on frustum will be asked in vertical position only.
(2) Hidden lines are not required in isometric projection.
Unit II: Machine Drawing (as per SP46: 2003) : 118 Periods
A. Drawing of machine parts 36 Periods
(i) Drawing to full size scale with instruments.
(Internal choice will be given between any two of the following).
Introduction of threads: Standard profiles of screw threads square, knuckle, B.S.W.,