Mechanics of Machines , Question Paper of B.Tech 4th Semester,Download Previous Years Question Paper 1

Roll No.

Total No. of Questions: 09]

B. Tech. (AE) (Sem.4th)

Mechanics of machines

Subject Code:-BTAE – 402

Paper ID –A162

Time: 3 Hrs.

INSTRUCTION TO CANDIDATES:

l) Section A is Compulsory.

 2) Attempt any Four Questions from section - B

3) Attempt any Two Questions from section - C

Section – A

Q1) Explain Briefly:

a) What is meant by the term mechanism?

b) What is the significance of the term inertia force?

c) What is the function of a counter shaft pulley? Explain

d) List some important materials used for manufacturing ropes.

e) What is meant by dwell time in the context of cams?

f) Steam Turbines do not need flywheels. Comment

g) Discus the significance of the term, coefficient of fluctuation of sped.

h) Explain what is sensitivity of a governor?

i) List two main limitations of a watt governor.

j) What are the main consequences of partial balancing of reciprocating parts (only list the name of consequences)?

Section – B

Q2) Explain what is a double slider crank mechanism? Name al the inversions of this mechanism.

Q3) For a reciprocating engine, prove that  

Where letters have their usual meaning

Q4) Differentiate between the following terms in the content of cams:

a) Period of ascent and period of decent

b) Base circle and prime circle.

Q5) Explain Why in a reciprocating masses system, only partial balancing can be achieved.

Q6) Define the terms effort and power of a governor. Derive an expression for power of a porter governor.

Section-C

Q7) Calculate the minimum sped of a propel governor, which has equal arms each 20mm and pivoted on the axis of rotation. The mass of each bal is 4 kg and the central mass on the sleeve is 20 kg. The extension arms of the lower links are each 60 mm long and parallel to the axis when the minimum radius of the bal is 10 mm.

Q8) A 270 cm long shaft caries three pulleys, two at its ends and the third at midpoint. The two end pulleys have masses 48 kg and 20 kg and their centre of gravitas are 1.5 cm and 1.25 cmrespectively from the axis of the shaft, the middle pulley has mass 56 kg and its C.G is 1.5 cm from the shaft axis. The pulleys are so keyed to the shaft hat he assembly is in static balance. The shaft rotates at 30 rpm in two bearings 180 cm apart with equal over hangs on either sides. Determine the relative angular position of the pulleys.

Q9) Determine the maximum power that can be transmitted using a belt of 10 mm x10 mm with an angle of lap of 160o. The density of the belt 10^-3 g/mm³ and = 0.25. The tension in the belt should not exceed 15N/mm²