Engineering Mechanics objective questions with answers part3

Q1. A sample of metal weighs 219 gms in air, 180 gms in water, 120 gms in an unknown fluid. Then which is correct statement about density of metal
(A) density of metal can’t be determined
(B) metal is twice as dense as water
(C) metal will float in water
(D) metal is twice as dense as unknown fluid

Q2. The C.G. of a solid hemisphere lies on the central radius 3r
(A) at distance — from the plane base 3r
(B) at distance — from the plane base 3r
(C) at distance — from the plane base 3r
(D) at distance — from the plane base or

Q3. The C.G. of a plane lamina will not be at its geometrical centre in the case of a
(A) right angled triangle
(B) equilateral triangle
(C) square
(D) circle

Q4. The C.G. of a right circular solid cone of height h lies at the following distance from the base
(A) h/2
(B) J/3
(C) h/6
(D) h/4

Q5. The M.I. of hollow circular section about a central axis perpendicular to section as compared to its M.I. about horizontal axis is
(A) same
(B) double
(C) half
(D) four times

Q6. Which of the following is the example of lever of first order
(A) arm of man
(B) pair of scissors
(C) pair of clinical tongs
(D) All of these

Q7. A pair of smith’s tongs is an example of the lever of
(A) first order
(B) second order
(C) third order
(D) fourth order.

Q8. In the lever of third order, load W, effort P and fulcrum F are oriented as follows
(A) W between P and F
(B) F between W and P
(C) P between W and F
(D) W, P and F all on one side

Q9. The angle which an inclined plane makes with the horizontal when a body placed on it is about to move down is known as angle of
(A) limiting friction
(B) repose
(C) kinematic friction
(D) static friction.

Q10. In actual machines
(A) mechanical advantage is greater than velocity ratio
(B) mechanical advantage is equal to velocity ratio
(C) mechanical advantage is less than velocity ratio
(D) mechanical advantage is unity

Q11. The unit of force in S.I. units is
(A) kilogram
(B) newton
(C) watt
(D) joule

Q12. The unit of work or energy in S.I. units is
(A) newton
(B) kilogram meter
(C) watt
(D) joule

Q13. Forces are called concurrent when their lines of action meet in
(A) one point
(B) two points
(C) perpendicular planes
(D) different planes.

Q14. Forces are called coplanar when all of them acting on body lie in
(A) one point
(B) one plane
(C) different planes
(D) perpendicular planes

Q15. A force acting on a body may
(A) introduce internal stresses
(B) balance the other forces acting on it
(C) retard its motion
(D) All of these

Q16. Which is the correct statement about law of polygon of forces ?
(A) if any number of forces acting at a point can be represented by the sides of a polygon taken in order, then the forces are in equilibrium
(B) if any number of forces acting at a point can be represented in direction and magnitude by the sides of a polygon, then the forces are in equilibrium
(C) if a polygon representing forces acting at a point is closed then forces are in equilibrium
(D) if any number of forces acting at a point can be represented in direction and magnitude by the sides of a polygon taken in order, then the forces are in equilibrium

Q17. Effect of a force on a body depends upon
(A) magnitude
(B) direction
(C) position or line of action
(D) All of these

Q18. If a number of forces act simultaneously on a particle, it is possible
(A) not a replace them by a single force
(B) to replace them by a single force
(C) to replace them by a couple
(D) to replace them by a couple and a force

Q19. A force is completely defined when we specify
(A) magnitude
(B) direction
(C) point of application
(D) All of these

Q20. 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 as per the principle of
(A) independence of forces
(B) dependence of forces
(C) balance of force
(D) resolution of forces