MOCK EXAM PAPER FOR PRACTICE; EME-101; ENGINEERING MECHANICS

Printed Pages:4                                    Paper Code: EME-101                                                     

 

B.  Tech –1^st Year (SEM.I)

Pre University Examination, May2012 – 13

Engg.Mechanics

Time:   3hrs                                                                 Total Marks:  100                                        

Note:   (1)        Attempt all questions.

(2)        Be precise in your answer.

Section-A

Tick the appropriate answer:

1. Three forces P, 2P and 3P are exerted along the directions of three sides of equilateral triangle. Their Resultant is 

  a) √3P               b) 3√3P               c) 3P                d) none of the above

2. If two forces P and Q act at an angle Ө, the resultant of these two forces would make an angle α with P such that  

 a) tan α = Q Sin Ө  /  P-Q Sin Ө         b) tan α = P Sin Ө  / P+ Q Sin Ө       

 c) tan α = Q Sin Ө / P+ Q Cos Ө        d) tan α= P Sin Ө / Q - P Cos Ө  

3. The center of gravity of a semicircle  of radius r made of metal is 

 a) on the base                           b) on the perimeter             

 c) 3r/8 above the base              d) 4r/3π above the base.

4. The parallel axis theorem for moment of inertia is

 a) I_zz = I_xx + I_yy                           b) I_Gx= I_xx + AY²             

 c) I_Gx= I_xx - AY²                         d)   I_Gx= I_xx + AX²                 

Fill in the blanks:

5. A body is on the point of sliding down an inclined plane under its own weight. If the inclination of the plane to the horizontal is 30° degree the angle of friction will be----------------------.

6. The velocity of a particle falling from a height h just  before touching ground is ---------------

7. A beam is having more than two supports is called---------------------- beam and such beams are statically   -----------------.

8. A car moving with uniform acceleration covers 450m in a 5 seconds and covers 700m in the next 5 seconds interval. The acceleration of the car is……………. .m /s^2.

9. Varignon’s theorem is related to……………

10. A truss is said to be rigid in nature when there is no --------------- on application of any external --------------------.             (2x 10=20)

Section-B

Attempt any two parts from each question.           (3x10 = 30)

 Q.1. (a) Define parallelogram law of forces and lami’s theorem.

(b) Find the resultant of the force system given in figure-2, Also find its position:

 (c) A uniform ladder weighting 200 N and length 6m is placed against a vertical wall in a position where its inclination to the vertical is 30 degree. A man weighting 600N climbs the ladder. At what position will he induce slipping? Take coefficient of friction μ = 0.2 at both the contact surfaces of ladder.

Q.2(a) How are the trusses classified? What are the assumptions taken while analyzing a plane truss?

 (b) Draw the reactions for the beam AB loaded through the attached strut.

 (c) Find the reaction in the cantilever beam shown in figure:

Q.3. (a) Define Parallel axis theorem and Perpendicular axis theorem.

(b) Find the Moment of Inertia of the I section shown in figure-5 about x-x and y-y axes.

(c) Derive an expression for mass moment of inertia of a right circular cone of base  radius R, height H and mass M about its axis.   

Section-C

 (5x10=50)   

Q.1. (a) Define impulse. State and explain the D'Alemberts principle.

(b) The equation of motion of a particle moving in a straight line is given by  the equation s =16t +4t²-3t³ where s is the total distance covered from the starting  point in meter at the end of t seconds. Find

(i) Displacement, velocity and acceleration 2 seconds after the start

(ii) the displacement and acceleration when velocity is zero

(iii) the maximum velocity of the particle.

(c) Define the following terms:    i) inertial force (ii) angle of repose (iii) coplanar non concurrent force system (iv) angular momentum 

 

Q.2(a) A car moving with an constant acceleration from rest in the first 50 sec, then in the next 40 second it moves with a constant velocity, in the next 20 second it comes to rest. Find the maximum and average velocity and the acceleration of the car:

(b)