MODEL QUESTION PAPER
B.E. Degree Examinations
Mechanical Engineering
Time : 3 Hours Maximum Marks : 100
Answer All Questions
PART - A 10 x 2 = 20 Marks
1. Sketch the stress-strain diagram for a ductile specimen and indicate its salient features.
2. Indicate the type of fit used in the assembly of bush in the big-end of the connecting rod of an automobile.
3. Define ‘endurance limit’ in design
4. Indicate the type of fit specified by 120 H7 p6 in a drawing.
5. Mention any two desirable properties of the material used in an automobile piston.
6. Sketch and indicate the salient parts of a flange coupling.
7. Mention the stresses induced in a taper key used in a coupling.
8. What is a ‘bearing characteristic number’.
9. Mention the names of any four theories of failure.
10. Define ‘coefficient of fluctuation of speed’ in a flywheel.
PART – B 5 x 16 = 80 Marks
11. i) A load of 5 KN is to be raised by means of a steel wire. Find the minimum diameter required, if the permissible stress in the wire is not to exceed 100 N /mm2 (4 Marks) ii) A square bar of 20 mm x 20 mm in section is subjected to a bending moment of 1000 Nmm. Calculate the stress induced in the top and bottom fibres of the bar. What will be stress in the above fibres, if the bar is additionally acted upon by a tensile stress of 50 N/mm2 along the axis. (6 Marks) iii) A circular shaft is to transmit a torque of 500 Nmm at a speed of 1000 rpm. Find out the diameter of the shaft, if the permissible shear stress in the shaft material is 70 N/mm2. (6 Marks)
12.a) A shaft is supported by two bearing arranged 1 m apart, A 600 mm diameter pulley is mounted at a distance of 300 mm to the right of the left hand bearing and this drives a pulley directly below it with the help of a belt having maximum tension of 2.25 kN. Another pulley of 400mm diameter is placed 200 mm to the left of the right hand bearing and is driven with the help of an electric motor