QUESTION BANK : ENGINEERING MECHANICS

Compiled by Er. Subhankar Karmakar

Unit: 1 (Force System)

VERY SHORT QUESTIONS (2 marks):

1)      What is force & force system?

2)      What is equilibrium? What are the conditions of equilibrium?

3)      Distinguish between coplanar concurrent & coplanar non-concurrent forces.

4)      State & explain the law of transmissibility of forces.

5)      What is moment? What is couple?

6)      State and explain the Varignon’s theorem of moment.

7)      What are the characteristics of couple?

8)      What are parallel forces?

9)      State Lami’s theorem of equilibrium of forces?

10)  Where do we can apply Lami’s theorem?

11)  Explain the terms Resultant & equilibrant?

12)  What is friction? On what factors frictional force depends?

13)  Explain the term Ladder Friction?

14)  What is angle of friction, angle of repose, co-efficient of friction?

15)  Explain the concept of Limiting friction.

16)  Explain the cone of friction. Also discuss it’s physical significance?

17)  State Coulomb’s law of dry friction?

18)  What is a belt drive? Explain the term angle of contact or lap angle.

19)  Explain the term Torque, Couple and Moment?

20)  Distinguish between static and dynamic friction.

BROAD QUESTIONS (5 marks / 10 marks)

1)      Classify Force systems with proper examples.

2)      State & prove Lami’s theorem.

3)      State & prove Varignon’s theorem of moment.

4)      What is the resultant of a force system? How can we determine the resultant?

5)      What are support reactions? Describe different types of loading.

6)      What is distributed loading? Explain UDL & UVL with examples.

7)      What is a fixed supports? Explain the term reaction moment?

8)      State & explain the principle of superposition.

9)      Show that a force at a point can be reduced to a force-couple system at another point on the same plane.

10)  What is the meaning of Equivalent System?

11)  What is Free Body Diagram or FBD?

12)  Prove that for a belt drive, (T₁/T₂) = e^μθ

 

NUMERICALS: (10 marks)

(1) Two rigid rod BA & CA are joined together at point A as shown in the figure. Now a weight of 200 kN is placed at point A. Find the reaction forces in the rod AB & AC.

    [ R_AC = 292.38 kN,  R_AB = 155.57 kN]

 

(2) A weight of 40 kN is suspended by two cables as shown in the figure. Find the tensions T₁ & T₂ in the cables. 

 3) On a square plate ABCD four forces are applied as shown in the figure. Find the resultant of the force system.

         

          4) A uniform bar AB length L and weight W lies in a plane with its ends resting on two smooth surfaces on OA and OB. Find angle θ for equilibrium of bar.

             [θ = 30° ]