Tuesday 8 November 2011

SHORT QUESTIONS: UNIT-1; FORCE SYSTEM

As new pattern has been issued by MTU for B. Tech first year EME-102 / EME-201:


Section A contains short questions, 2 from each unit & total 10 questions each of 2 marks.
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1) What is a Couple?

Ans: Two unlike parallel, non-collinear forces having same magnitude from a Couple. The distance between two forces is known as arm or lever of the couple.

        Properties of a Couple:

        (i) Two unlike parallel, non-collinear forces having same magnitude from a Couple.
       (ii) The resultant of a couple is always zero.
      (iii) The moment of a couple is the product of one of the forces and moment arm of the couple.
      (iv) A couple cannot be balanced by a single force.
       (v) It can be balanced only by another couple of opposite nature.
      (vi) The moment of a couple is independent of the moment center.
     (vii) The effect of a couple is unchanged if
                         (a) it is shifted to any other position in its plane or to any other parallel plane
                         (b) it is rotated through any angle in its plane.



(2) What is Moment of Inertia of a Mass M?


MOI or MOMENTS OF INERTIA is a physical quantity which represents the inertia or resistances shown by the body against the tendency to rotate under the action external forces on the body. It is a rotational axis dependent function as its magnitude depends upon our selection of rotational axis.

If a body of elemental mass dM rotates about an axis r distance from the body, the elemental Mass Moment of Inertia will be r².dM and total moment of inertia of the body of mass M about the axis of rotation will be the integration of the elemental mass moment of inertia ie. ∫r².dM

(3) What is a force system?






a)     State Lami’s theorem of equilibrium of force.
b)    What is Angle of Friction? State coulomb’s Law of Dry Friction.
c)     Explain the Maxwell’s equation of truss.
d)    What is point of contraflexure?
e)     What is area moment of inertia? What is its unit?
f)     What is the difference between centroid and center of gravity?
g)    What is angular acceleration? What is kinetic energy?
h)    What is inertial force?
i)      What is normal stress and normal strain?
j)      Explain the term poisson’s ratio?

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