GTU 110013 Engineering Graphics Dec 2011 Question Paper

B.E. Sem- 1st Regular Examination December 2011

(Common to all Branches)
Date: 21-12-2011
Time: 10:30am-1:30pm (3 hrs)
Maximum Marks: 70

Instructions:

1. Attempt any FIVE questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
4. Lines, dimensions etc. should be as per BIS SP-46.
5. Retain all construction line.

1. a) Explain the difference between Ist angle and IIIrd angle orthographic projection. 3 marks

Ans: Refer article 7.7 and 7.9 page 7.5-7.7 of ED - Basant Agrawal, TMH.

1. b) Figure No.1 shows the Pictorial view of an object. Draw the following views using first angle projection method (a) Sectional Front elevation looking from direction X, take section along A-A (b) Top view (c) Side view from left. Show all dimensions. 11 marks

Ans: Refer article 7.22-7.26 page 7.20-7.24 of ED - Basant Agrawal, TMH.

2. a) Figure No. 2 shows the four bar chain mechanism O1ABO2 and the dimensions of are as below :
O1A = O2B = 1125 mm connecting link AB = 375 mm
Draw the locus of midpoint M of AB, considering O1A as driving link. 7 marks

Ans: Similar to problem 6.18 page 6.19 of ED - Basant Agrawal, TMH.
2. b) A circle of 50 mm diameter rolls along the circumference of another circle of 150 mm diameter from outside. Draw the path of a point P on the circumference of the rolling circle for one complete revolution and name the curve. 7 marks
Ans: Refer problem 6.2 page 6.2 of ED - Basant Agrawal, TMH.

3. a) A straight AB has its end A 10 mm above HP and end B 50 mm in front of the V.P. Draw the projections of line AB, if it is inclined to H.P. by 30° and to V.P. by 45° and it is 50 mm long. 7 marks
Ans: Similar to problem 9.21 page 9.25 of ED - Basant Agrawal, TMH.3. b) ABCD is a rhombus of diagonals AC = 110 mm and BD =70 mm. Its corner A is in the H.P. and the plane is inclined to H.P. such that the plan appears to be a square. The plan of diagonal AC makes an angle of 20° to the V.P. Draw the projections of the plane and find its inclination with H.P. 7 marks
Ans: Similar to problem 10.24 page 10.25 of ED - Basant Agrawal, TMH. Problem is tough because there is a need to determine apparant angle.

4. a) The top view of 75 mm lone line AB measures 65 mm, while the length of its front view is 50 mm. Its one end A is in the H.P. and 12 mm in front of the V.P. Draw the projections of line AB and its inclinations with the H.P. and the V.P. 7 marks
Ans: Refer problem 9.26 page 9.29 of ED - Basant Agrawal, TMH.

4. b) The top plan of a pair of equal legs AB and AC of compass appears as an isosceles triangle having base 50 mm and vertex angle at 45°. Actual lengths of compass legs AB and AC are 120 mm. Assume points B and C on H.P. and line connecting B and C is perpendicular to V.P. Draw the projections and find (i) the actual angle between two legs (ii) the height of point above HP and (iii) angle of plane, containing compass, makes with H.P. 7 marks
Ans: This problem is on the application of a straight lines.

5. a) Engineering graphics is a language of all persons involved in engineering activities. Discuss the statement.3 marks
Ans: Refer article 1.1 page 1.1 of ED - Basant Agrawal, TMH.
A drawing drawn by an engineer having engineering knowledge for the drawing purposes is an engineering drawing. It is meant for communicating his ideas, thoughts and designs to others. Engineering drawing is a starting point of all engineering branches such as Mechanical, Production, Civil, Electrical, Electronics, Computer science, Chemical etc. It is spoken, read, and written in its own way. Engineering drawing has its own grammar in the theory of projections, its idioms in conventional practices, its punctuations in the types of lines, its abbreviations, symbols and its descriptions in the constructions.

5. b) A cone, base 75 mm diameter and axis 80 mm long is resting on its base on the H.P. It is cut by a section plane perpendicular to the V.P., inclined at 45° to the H.P. and cutting the axis at a 35 mm from the apex. Draw front view, sectional top view and true shape of the section. 11 marks
Ans: Refer problem 12.24 pages 12.26 of ED - Basant Agrawal, TMH.

6. a) Write short note on BIS SP-46 engineering drawing standard. 3 marks

Ans: Refer this website Engineering Drawing and Graphics- Basant Agrawal.

6. b) A pentagonal pyramid, side of base 40 mm and height 80 mm, is resting on its base with one of the edges of the base away from V.P. is parallel to V.P. It is cut by an AIP bisecting the axis, the distance of the section plane from the apex being 20 mm. Draw the elevation and sectional plan of pyramid and draw the true shape of the section. Also find the inclination of the section plane with the H.P. 11 marks
Ans: Refer problem 12.19 pages 12.21 of ED - Basant Agrawal, TMH. The problem is tough there is a need to determine inclination of the plane. Hints: (i) Draw a circle/arc of 20 mm radius with apex as the centre. (ii) draw a line passing through the mid-point of the apex and tangent to the drawn circle.

7. a) Define development of surfaces and state its applications in engineering field. 3 marks
Ans: Refer article 13.1 page 13.1 of ED - Basant Agrawal, TMH.

7. b) A hollow square pyramid, side of base 45 mm and height 65 mm, is resting on H.P. on its base with all sides of base equally inclined to V.P. A square hole of size 20 mm is drilled through the pyramid. Sides of the square hole are equally inclined to H.P. Axis of the square hole and pyramid intersects at right angle 20 mm above the base of the pyramid. Axis of the hole is perpendicular to V.P. Draw the plan, elevation and development of the lateral surfaces of the pyramid. 11 marks
Ans: Refer problems 13.29 to 13.26 pages 15.18-15.22 of ED - Basant Agrawal, TMH. This is also one of the tough problem.