3)State the materials used for manufacturing springs.
4)Define Solid length.
5)Define free length.
6)Write the formula to find Pitch angle of a spring.
7)Define Pitch of the spring.
8)Define slenderness ratio of a spring.
9)Define Stiffness of a spring.
10)Define Endurance stress of a spring.
11)Define Hysterisis of a spring.
12)Define Nipping of a leaf spring.
13)What are the applications of helical springs?
14)Write down the formula used for finding the stiffness of two springs when they are in parallel with their resulting displacements not equal.
15). Sketch the stress-strain diagram for a ductile specimen and indicate its salient features.
16)Indicate the type of fit used in the assembly of bush in the big-end of the
17)connecting rod of an automobile.
18)Define ‘endurance limit’ in design
19)Indicate the type of fit specified by 120 H7 p6 in a drawing.
20)Mention any two desirable properties of the material used in an automobile piston.
21)Sketch and indicate the salient parts of a flange coupling.
22)Mention the stresses induced in a taper key used in a coupling.
23)What is a ‘bearing characteristic number’.
24)Mention the names of any four theories of failure.
25)Define ‘coefficient of fluctuation of speed’ in a flywheel.
1. A shaft is supported on bearings A and B, 800 mm between centers. A 20o straight tooth spur gear having 600 mm pitch diameter, is located 200 mm to the right of the left hand bearing A, and a 700 mm diameter pulley is mounted 250 mm towards the left of the bearing B. The gear is driven by a pinion with a downward tangential force while the pulley drives a horizontal belt having 180o angle of wrap. The pulley also serves as a flywheel and weighs 2000 N. The maximum belt tension is 3000 N. Design the shaft with proper material of shaft.
2. A mild steel shaft carries two gears, C and D located at distances 240 mm and 380 mm respectively from the centre lines of the left and right bearings. The diameter of gear C is 580 mm and diameter of gear D is 180 mm. The power is delivered to gear C and taken out at gear D in such a manner that tooth pressures Pc and Pdat gear C and D respectively act vertically downward. If the shaft transmits 14 H.P at 100 rpm .Calculate the diameter of shaft. Safe tensile stress is 8 KN/mm2 .Gear C weighs 1000 N and gear D weighs 400 N.
3.A shaft is supported by bearing 1000 mm apart. Gear B has 40 teeth and 10 mm module. It is located 400 mm left to the right hand bearing and is driven by gear A directly below it. A belt pulley C, 500 mm in diameter is located 600 mm to the right of left hand bearing and drives another bigger pulley directly behind it. The ratio of tensions is 3:1 with tight side on top. The angle of wrap is 1500 .The gear teeth are 20o involute form. The gear transmits 35 KW at 400 rpm. Determine the shaft diameter.
4.The two helical compression springs are placed one inside the other. The outer spring is
made of 38 mm diameter round bar stock with six active terms and has 225 mm outer
diameter of helix. The inner spring is of 25 mm diameter bar with 9 active turns and has
140 mm outer diameter of helix. The free height of outer spring is 19 mm more than the
inner spring. Find the deflection of each spring for total of 90 KN. Also determine the
load shared by each spring and stresses induced in each spring. Modulus of rigidity for
spring material is 85 KN/mm2.
5.Design a spring for a balance to measure 0 to 1000 N over a scale of length 80 mm. The
Spring is to be enclosed in a closing of 25 mm dia. The approximate number of turns is 30.
Also calculate the maximum shear stress induced. Take G = 85 GPa.
6. A helical compression spring of the exhaust valve mechanism is initially compressed with a pre-load of 375 N. When the spring is further compression and the valve is fully opened, the torsional shear stress in the spring wire should not exceed 750 N/mm2. Due to Space limitations, the outer diameter of the spring is not exceed 42 mm. The spring is to be designed for minimum weight. Calculate the wire diameter and the mean coil diameter of the spring.
7.A piston of a reciprocating compressor has a diameter of 60mm. The maximum pressure on thepiston fall is 1.25MN/m2.Assuming the gudgeon pin passing through the small end of the connectingrod can be safely loaded in shear up to 10MN/m2, Calculate the minimum diameter of the gudgeon pin.
8.Design a connecting rod for a petrol engine for the following data:
Diameter of the piston = 68 mm
Stroke length = 80 mm
Length of connecting rod = 160 mm
Maximum explosion pressure = 3.5 N/ mm2
Mass of reciprocating parts = 2.5 kg
Speed = 4000 rpm
Compression ratio = 8 :1
9.The connecting rod of a petrol engine is to be designed for the following
Piston diameter 80 mm
Stroke 120 mm
Weight of the reciprocating parts 15N
Length of connecting rod 240 mm
Max speed 2800 rpm.
Explosion pressure corresponding to 10° of crank angle is 3 MPa.
Factor of safety 6
If the connecting rod is to be made of 40Cr1 Steel, find the dimensions of
the I-section connecting rod.
10.Design a suitable spring for the exhaust valve of a petrol engine. The spring should be capable of exerting a net force of 360N when the valve is open and 220N when it is closed. The maximum inside diameter of the spring is 25mm. The compression in spring is 8mm.
11. Design and draw suitable flywheel for a four stroke four cylinder 133 kW
engine running at 375 rpm. Due to space restriction the flywheel
diameter should not exceed 1.2m
13. A transmission shaft is supported on two bearings which are 1m apart.
Power is supplied to the shaft by means of a flexible coupling, which is
located to the left of left hand bearing. Power is transmitted from the
shaft by means of a belt pulley, 250 mm diameter, which is located at a
distance of 300 mm from the left hand bearing. The mass of the pulley is
20 kg and the ratio of belt tension on tight and slack sides is 2:1. The belt
tensions act vertically downward. The shaft is made of steel with yield
stress 300N/mm2 and the factor of safety is 3. Determine the shaft
diameter, if it transmits 10 kW power at 360 rpm from the coupling to
2.Distinguish between Line and End standards.Give examples.
3.Define Abbe’s principle of measurement.
4.Define static and dynamic characteristics (static and dynamic response) of a measuring instrument.
5.Discuss about fundamental and derived units in detail.
UNIT – 2
1.What is wringing of slip gauges?
2.What are the standards of slip gauges?
3.What is a Limit gauge?Write the Taylor’s principle of gauge design.
4.Explain the working principle of Laser micrometer.
5.What is a comparator?Classify comparators.
PART – B QUESTIONS ( 16 marks QUESTIONS)
1.Write down the differences between Precision & Accuracy
2.Differentiate random errors from systematic errors
3.Explain the types of errors with examples
4.Explain the causes of errors with suitable examples
5.Explain the classification of measuring methods.
UNIT – 2
1.Explain the working principle of Johansson ‘Microkator’ with a neat sketch
2.Explain with a sketch the working principle of Sigma comparator
3.With a neat sketch, Describe the principle of Solex Pneumatic Comparator
4.With a neat sketch, explain the working principle of micro optic Autocollimator.
5.With a neat sketch, explain the working principle and applications of Angle Dekkor.
6.Briefly explain the various elements of Optical Bevel Protractor with a neat sketch.
Q.1Bring out differences between form joint and spring caliper. Draw neat sketches of both types for measuring diameters – inside and outside. (10)
Q.2Describe the construction of a micrometer and the procedure of reading on it. The sleeve of a micrometer is graduated in mm. The thimble is graduated in 50 divisions. It takes two complete rotations of thimble for spindle to advance through one mm. During a particular measurement 8 divisions on sleeve are clear of the thimble and 10th division is coinciding with the reference line. Give the least count and reading. (10)
Q.3What function does LVDT serve in measurement? Explain its function with the help of a sketch. Explain the principle of a strain gauge.(10)
Q.4What is a comparator? State different types of comparators. Compose mechanical comparator with electrical comparator. What is the principle of a pneumatic comparator? (10)
Q.5What is a side bar? Explain its use with the help of a dial indicator. How do you make a gauge block build up? (10)
Q.6Sketch a universal level protractor and state why it is called universal in comparison with a normal protractor. Explain what angle gauges are and where they are used? (10)
Q.7State principle of optical projector and explain how the image is obtained on the screen. What are different applications and advantages of optical projector in production? (10)
Q.8What is a coordinate measuring machine and what advantages does it offer in measuring various manufactured parts. “In computer aided manufacturing, CMM has an important role to play”. Justify this statement. (10)
Q.9Two closely placed light sources emit light waves of same angular frequency but different phase angles. Write down equations for two waves. On reaching a point at a distance D from the sources the two waves are superimposed. Find the resultant wave. Explain constructive and destructive interference and their results. (10)
Q.10What are different light sources used in interferometer? Explain how interferometry can be used in finding vertical difference between two points on a machined surface. (10)