Maharashtra State Board of Technical Education 2008 Diploma Mechanical Engineering for Design of Machine Element - Question Paper

Sample Test Paper-I

Course Name : Diploma in Mechanical Engineering
Course Code : ME

9150

Semester : 6th
Subject Title : Design of Machine Elements
Marks : 20 Time: one Hour

Instructions:

1. All ques. are compulsory
2. Illustrate your answers with neat sketches wherever necessary
3. Figures to the right indicate full marks
4. presume suitable data if necessary
5. Preferably, write the answers in sequential order
Q.1 Attempt any 2 of the following: 08 Marks
a) describe i) Resilience ii) Fatigue Strength iii) Creep iv) Endurance Limit
b) Write any 4 strength equations in the design of Cotter Joint with relevant
sketches
c) What is the effect of key on the strength of shaft?

Q.2 Attempt any 2 of the Following: 12 Marks
a) Make a neat sketch of knuckle joint and provide its design procedure with strength
equations.
b) A shaft made of steel is needed to transmit 100KW at 200 rpm. The support
length of the shaft is 300mm. It carries 2 pulleys every weighing 1000 N supported
at a distance of 1000mm from the ends respectively. Assuming the safe value of
stress, determine the diameter of the shaft.

c) Design and make a neat sketch of muff-coupling which is used to connect 2 steel shafts
transmitting 50 KW at 300 rpm. The permissible shear and crushing stresses may be 50 MPa
and 100 MPa respectively. The material for the shaft is cast Iron or which the allowable shear
stress may be presumed as 15 MPa.


Sample Test Paper-II

Course Name : Diploma in Mechanical Engineering
Course Code : ME

9150

Semester : 6th
Subject Title : Design of Machine Elements
Marks : 20 Time: one Hour

Instructions:

1. All ques. are compulsory.
2. Illustrate your answers with neat sketches wherever necessary.
3. Figures to the right indicate full marks.
4. presume suitable data if necessary.
5. Preferably, write the answers in sequential order.
Q.1 Attempt any 2 of the following: 08 Marks
a) provide classification of bearings.
b) describe i) Spring Index ii) Stiffness iii) Free length iv) Solid Length
c) State the importance of shape and colour in the design of Aesthetics

Q.2 Attempt any 2 of the following; 12 Marks
a) A vertical 2 begin square threaded screw of 100mm mean diameter and 20mm
pitch supports its vertical load of 18 KN. The axial thrust is taken up by a collar
bearing of 250mm outside diameter and 100mm inside diameter. obtain the forse
needed at the end of a lever which is 400mm long in order to lift the load. The coefficient of friction ranging from screw and the nut is 0.15 and for collar bearing is 0.2.
b) The inside dimensions of the rotor of a 100 KW, 960 rpm motor is 100 cm. Starting
torque may be presumed as 200% of running torque. The maximum belt pull on the
motor shaft is 1000 N. The shaft centre is 62.5 cm above the base line. There are
four foundation bolts spaced 65 cm on centres axially and 110 cm on centres normal
to the axis. The width of the bore is 125 cm. Determine the load on every bolt and
the proper diameter of the bolts. Permissible tensile stress intensity in the bolt is 80
MPa.
c) Design a close-coiled helical compression spring for a service load ranging from
2000 n to 3000 N. The axial deflection of the spring for the load range is six mm.
presume a spring index of 5. The permissible shear stress intensity is 4000n/mm2 and
modulus of rigidity is 84 KN/mm2.



Earning:   Approval pending.