GATE Mechanical Engineering Mechanics Set1

1 As per Lami's theorom if  a body is in equilibrium under action of three forces, each force is proportional to
A) Sine of angle between other two forces.
B) Cosine of angle between other two forces.
C) Tan of angle between other two forces.
D) Non of above.

ANS: A) Sine of angle between other two forces.

2. In a perfect load bearing frame what is the necessary condition:
A) m =  2 j +3
B) m =  2 j -3

C) m =  j
D) j =  2 m +3
where m = no of members
          j = no of joints
ANS: B) m =  2 j -3

3. In Static friction
A) Force of friction acts in opposite direction of that in which body tends to move.
B) The force of friction bears a constant ratio to Normal Reaction between two surfaces.
C) Force of friction depends upon roughness/smoothness of surfaces.
D) All of above.

ANS: D) All of above.


4. In Space, when one body sides over another body the force of friction will be
A) m1*g
B) m2*g

C) (m1 + m2)*g
D) 0

ANS: D) 0. As in space the gravity does not exist the Normal reaction between two surfaces will be 0 hence the force of friction will be zero.

5. In a machine what does Mechanical Advantage / Velocity Ratios signify
A) Effort required (P) to lift load (W).
B) Efficiency of the machine
C) Reversibility or Irreversibility of machine
D) None of above.
ANS: B) Efficiency of the machine


GATE Mechanical Engineering Mechanics Set 2