Engineering Mechanics Objective Questions - Set 07 - ObjectiveBooks

# Practice Test: Question Set - 07

1. Two bodies of masses m1 and m2 are hung from the ends of a rope, passing over a frictionless pulley as shown in the figure below. The acceleration of the string will be

(A) g (m1 - m2)/(m1 + m2)
(B) 2g (m1 - m2)/(m1 + m2)
(C) g (m1 + m2)/(m1 - m2)
(D) 2g (m1 + m2)/(m1 - m2)

2. The velocity ratio of a differential wheel and axle with 'D' as the diameter of effort wheel and d1 and d2 as the diameters of larger and smaller axles respectively, is
(A) D/(d₁ + d₂)
(B) D/(d₁ - d₂)
(C) 2D/(d₁ + d₂)
(D) 2D/(d₁ - d₂)

3. Which of the following is not the unit of power?
(A) kW (kilowatt)
(B) hp (horse power)
(C) kcal/sec
(D) kcal/kg sec

4. Non-coplanar non-concurrent forces are those forces which
(A) Meet at one point, but their lines of action do not lie on the same plane
(B) Do not meet at one point and their lines of action do not lie on the same plane
(C) Do not meet at one point but their lines of action lie on the same plane
(D) None of the above

5. The unit of force in S.I. units is
(A) kilogram
(B) Newton
(C) Watt
(D) Dyne

6. A number of forces acting at a point will be in equilibrium, if
(A) All the forces are equally inclined
(B) Sum of all the forces is zero
(C) Sum of resolved parts in the vertical direction is zero (i.e. ∑V = 0)
(D) None of these

7. The weight of a body is due to
(A) Gravitational pull exerted by the earth
(B) Forces experienced by body in atmosphere
(C) Force of attraction experienced by particles
(D) Gravitational force of attraction towards the centre of the earth

8. The efficiency of a lifting machine is the ratio of
(A) Output to the input
(B) Work done by the machine to the work done on the machine
(C) Mechanical advantage to the velocity ratio
(D) All of the above

9. According to principle of moments
(A) If a system of coplanar forces is in equilibrium, then their algebraic sum is zero
(B) If a system of coplanar forces is in equilibrium, then the algebraic sum of their moments about any point in their plane is zero
(C) The algebraic sum of the moments of any two forces about any point is equal to moment of the resultant about the same point
(D) Positive and negative couples can be balanced

10. Moment of inertia of a triangular section of base (b) and height (h) about an axis passing through its vertex and parallel to the base, is __________ than that passing through its C.G. and parallel to the base.
(A) Nine times
(B) Six times
(C) Four times
(D) Two times

11. A trolley wire weighs 1.2 kg per meter length. The ends of the wire are attached to two poles 20 meters apart. If the horizontal tension is 1500 kg find the dip in the middle of the span
(A) 2.5 cm
(B) 3.0 cm
(C) 4.0 cm
(D) 5.0 cm

12. The algebraic sum of the resolved parts of a number of forces in a given direction is equal to the resolved part of their resultant in the same direction. This is known as
(A) Principle of independence of forces
(B) Principle of resolution of forces
(C) Principle of transmissibility of forces
(D) None of these

13. A particle moves along a straight line such that distance (x) traversed in 't' seconds is given by x = (t - 4), the acceleration of the particle will be given by the equation
(A) 6 - 8t
(B) 3 + 2t
(C) 6f - 8
(D) 6f - 4

14. The minimum force required to slide a body of weight 'W' on a rough horizontal plane is
(A) W sinθ
(B) W cosθ
(C) W tanθ
(D) None of these

15. The maximum frictional force which comes into play when a body just begins to slide over another surface is called
(A) Limiting friction
(B) Sliding friction
(C) Rolling friction
(D) Kinematic friction

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