Mathematics, Question Paper of B.Tech 4th Semester,Download Previous Years Question Paper 2

Roll No

Total No. of Questions : 09]

B.Tech. (AE-2011 Batch) (Sem.–4th)

MECHANICS OF MACHINES

Subject Code : BTAE-402

Paper ID : [A1162]

Time : 3 Hrs.

INSTRUCTIONS TO CANDIDATES :

1. SECTION-A is COMPULSORY consisting of TEN questions carrying

TWO marks each.

2. SECTION-B contains FIVE questions carrying FIVE marks each and

students have to attempt any FOUR questions.

3. SECTION-C contains THREE questions carrying TEN marks each and

students have to attempt any TWO questions.

SECTION-A

l. Answer briefly :

(a) What is meant by the term, ‘inversion’ ?

(b) Discuss the significance of inertia force.

(c) Belts are non-positive drives. Explain.

(d) Discuss the purpose of using cone pulleys.

(e) In the context of cams, explain the meaning of dwell period.

(f) Discuss the significance of the term - coefficient of fluctuation of

speed in governors.

(g) What does the area under the curve of a turning moment diagram represent ?

(h) How do you define stability of a governor ?

(i) What is the main difference between static and dynamic balancing ?

(j) List one main advantage of spring controlled governors over dead weight governors.

SECTION-B

2. With neat sketches, explain the inversions of a single slider crank mechanism.

3. Define the terms : piston effort, crank effort and thrust on the crank shaft bearings. What is the significance of each of these?

4. In the context of cams, explain and differentiate between the terms :

(a) Basic Circle and Prime Circle

(b) Pitch Point and Trace Point.

5. For a reciprocating mass system, deduce an expression for the swaying couple effect caused because of partial balancing.

6. Derive an expression for the effort and power of a porter governor. What is the significance of these terms?

SECTION-C

7. A Hartnell governor having a central sleeve spring and two right angled bell crank levers operates between 290 rpm and 310 rpm for a sleeve lift of 15 mm. The sleeve arms and the ball arms are 80 mm and 120 mm respectively. The levers are pivoted at 120 mm from the governor axis and mass of each ball is 2.5 kg. The ball arms are parallel to the governor axis at the lowest equilibrium speed. Determine the stiffness of the spring.

8. Four masses A, B, C and D are attached to a rotating shaft with radii 50 mm, 62.5 mm, 100 mm and 75 mm respectively. The distances between A and B, between planes B and C and between planes C and D are 600 mm each. The masses B, C and D are 20 kg, 10 kg and 8 kg respectively. If the shaft is in complete balance, find the angular positions of the four masses.

9. A belt of density 1 g/cm3 has a maximum permissible stress of 250N/cm2. Determine the maximum power that can be transmitted by a belt of 20 cm × 1.2 cm if the ratio of tight side to slack side tension is 2.