EG - Class 12 Pre Board 3 - Exam

St. COLUMBA’S SCHOOL

Ashok Place, N. Delhi – 110001

Pre-Board 3, March 2021

Class XII, Engineering Graphics

Time: 3 hrs                                                                                                      MM : 70

Instructions

1.       Attempt all questions.

2.       All dimensions are in mm.

3.       Follow the SP: 46-1988 codes (with first angle projections)

4.       Use both sides of the drawing sheet, if required.

5.       Missing or mismatching dimensions, if any, may be suitably assumed

6.       Diagrams are not to scale. Follow the dimensions only.

7.       Draw neat projections/ views.

  

Q 1 (a) Construct an Isometric scale of length 80 mm with subdivisions.                 (4)                             

 

       (b) Draw isometric projection of a hexagonal prism in

             the vertical position having base side 40 mm and height 70 mm.

             Two of the base edges are parallel to the VP.                                                      (7)

 

       (c) Draw the isometric projection of a pentagonal pyramid of base edge 30 mm

             and 60 mm height, is placed centrally on top of a hexagonal slab (prism) of

             base side 40 mm and height 30 mm.                                                                     (14)                                                 

 

Q 2 (a) Draw to scale 1: 1 the standard profile of Metric thread (Internal) of pitch

             50 mm. Give standard dimensions.                                                                 (7)

               

                                                            OR

             Draw to scale 1: 1 the FV, TV and SV of a hexagonal nut M 30 keeping its

             axis vertical. Give standard dimensions.

 

        (b) Sketch freehand FV and TV of a Collar Stud in horizontal position

               having diameter of 20 mm. Give standard dimensions.                                    (5)

                                                            OR

              Sketch freehand FV and TV of a Pan Head Rivet in the vertical position having

              diameter of 20 mm. Give standard dimensions.                                                                     

Q 3   Answer the following Multiple Choice Questions (MCQs).    (1 mark each)  (5)                                     

 

1.      Q1 Lines that are parallel to the Isometric Axes are called as?

(a)    Isometric Lines  (b) Parallel Lines  (c) Vertical Lines  (d) Slant Lines

2.      Q2 The word Isometric means?

(a)    Symmetrical       (b) Unequal measure    (c) Slanted  (d) Equal measure      

3.      Q3 The threads used in the common water bottle are?

(a)    Metric         (b) BSW               (c) Knuckle        (d) Square

4.      Q4 How many machine parts are there in a gib and cotter joint?

(a)    1                   (b) 2                     (c) 3                    (d) 4

5.      Q5 What is the shank length of a bolt in terms of its diameter, d?

(a)    4d                 (b) 2d                  (c) 2d + 6           (d) 2d + 1

 

 

Q 4  Fig below shows the ASSEMBLY of a Flange Pipe Joint. Disassemble its parts

         correctly and then draw the following views to 1:1 scale without changing the 

         position of the parts wrt the HP or the VP 

                                                                                                                                                  

(a)    Front view upper half in section of Flange A                                    (8)

(b)   Unsectioned Flange B                                                                        (6)

(c)    Front View and LH side view of the Gasket                                      (6)      

(d)   Front View and the RH Side View of the Hexagonal Nut                  (4)

Print tile, scale used, projection symbol and give all important dimensions.      (4)