Wednesday 21 November 2012

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


Printed Pages:4                                    Paper Code: EME-101                                                     


 
B.  Tech –1st 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) Izz = Ixx + Iyy                           b) IGx= Ixx + AY2             
 c) IGx= Ixx - AY2                         d)   IGx= Ixx + 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 /s2.
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)