Subject: Technical Drawing

Class: X

There will be one written paper of three hours duration carrying 80 marks and Internal Assessment of 20 marks.

The paper will be divided into two sections, A and B.

Section A will consist of a number of questions covering the entire syllabus. The candidates are to attempt three questions.

Section B will consist of questions which will require detailed answers. There will be a choice and candidates will be required to answer two questions in all from this section.

1. Plane Geometry

(i) Geometrical Constructions

(a) Division of a circle into equal parts (4, 6, 8, 12).
(b) A circle of given radius passing through two given points.
(c) An arc passing through three non-collinear points.
(d) An arc / a circle of given radius:

Touching a given straight line and passing through a given point.
Touching two straight lines which make a right angle / an acute angle / an obtuse angle between them.
Touching a given arc and a straight line touching two given arcs.

(e) Two circles touching each other externally and touching two straight lines making an acute angle between them, radius of one circle is given.
(f) A triangle / quadrilateral when its perimeter and the ratio of the lengths of sides given using divisions of the perimeter into proportional parts.
(g) A regular polygon (3, 4, 5, 6 sides) with special methods when length of its side is given.
(h) A regular octagon in a square when side of the square is equal to the distance between the parallel sides of the octagon.
(i) Inscribe / circumscribe a circle on a regular polygon up to 6 sides.
(j) A regular polygon (3, 4, 5, 6, 8 sides) when the radius of inscribed / circumscribed circle is given.
(k) Inside a regular polygon: To draw same number of equal circles as the number of sides of the polygon (up to 6 sides), touching one / two sides of the polygon and two of the other circles.
(1) Outside a regular polygon: To draw same number of equal circles as the number of sides of the polygon ( up to 6 sides ), touching one side of the polygon and two of the other circles.
(m) Regular hexagon and three equal circles inside it touching one / two sides of the hexagon and other two equal circles.
(n) A circle and inside it 3 / 4 / 5 / 6 smaller equal circles touching it internally and touching other two equal circles.
(o) Tangent / two tangents to a circle from a point outside the circle.
(p) External / internal common tangent / tangents to two given circles.

(ii) Templates

Redraw the given figure involving geometrical constructions and tangency.

(iii) Scales

(a) Definition / formula to find the Representative Fraction and the Scale length showing neat working.
(b) Construction of a Plain / Diagonal Scale.
(c) Show the given lengths on the scale.

2. Solid Geometry

Orthographic projections

(a) Lines and planes in the first / third quadrant: Front view and top view only

Line inclined to both the reference planes:

• Draw projections
• Find the true length when projections given.

Surface / plane:

• Surface inclined to one reference plane perpendicular to the other.
• Surface inclined to both the reference planes.

b) Solids:

Right regular solid such as prism and pyramid with the base as a regular polygon up to six sides, circular cylinder and cone in the first / third angle method of projection. Projections (front view, top view and side view) and development of surfaces (parallel / radial)

− Axis perpendicular to one reference plane and parallel to the other.
− Axis parallel to both the reference planes.
− Axis inclined to one reference plane and parallel to other. Use of auxiliary plane may be included. (Auxiliary elevation / plan).

Sections

Axis perpendicular to Horizontal Plane and parallel to Vertical Plane with a section plane parallel / inclined to one reference plane and perpendicular to the other (Figure showing Vertical Trace / Horizontal Trace should be given. Questions based on word problems should be excluded.)

− Sectional views.
− Development of lateral surface.
− True shape of a section.
− Auxiliary front / top view when auxiliary plane parallel to the section plane.

(c) Orthographic Views:

Conversion of a pictorial view (isometric / oblique) into orthographic views using the first / third angle method of projection.

(d) Sectional Orthographic Views:

− Conversion of a pictorial view (isometric / oblique) into sectional / half sectional view / views using the first / third angle method of projection.
− Conversion of given orthographic views into sectional / half Sectional views and adding the missing view.

(e) Isometric / Oblique Drawing:

− Copy the given figure.
− Conversion of the given orthographic view into an isometric / oblique view (Use of isometric scale is excluded

INTERNAL ASSESSMENT (20 Marks)

1. A file containing minimum 15 drawing assignments should be prepared.

2. A three dimensional model of a wooden joint should be made using thermocol which will help the students to learn assembly technique and procedure.

EVALUATION

The assignments / project work are to be evaluated by the subject teacher and by an External Examiner. (The External Examiner may be a teacher nominated by the Head of the school, who could be from the
faculty, but not teaching the subject in the section / class. For example, a teacher of Geometrical and Mechanical Drawing of Class XI may be deputed to be an External Examiner for Class X Technical
Drawing Projects.) The Internal Examiner and the External Examiner will assess the assignments independently.

Award of marks (20 Marks)

Subject Teacher (Internal Examiner) 10 marks

External Examiner 10 marks

The total marks obtained out of 20 are to be sent to the Council by the Head of the school.

The Head of the school will be responsible for the entry of marks on the mark sheets provided by the Council.

Courtesy: cisce.org