-: a k gaikar (ankushgaikar.wordpress.com) · 2017. 1. 16. · objective test 1 engineering...

-: A K GAIKAR (ankushgaikar.wordpress.com)

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Objective Test 1

Engineering Mechanics 16/01/2017

Time 1 hour No of questions 60 (each of 1 mark)

1. What is the branch of engineering mechanics which refers to the study of stationary

rigid body?

A. Statics

B. Kinetics

C. Kinematics

D. Dynamics

2. What is the branch of engineering mechanics which refers to the study of rigid body in

motion under the action of forces?

A. Statics

B. Strenght of materials

C. Kinematics

D. Dynamics

3. What is the branch of engineering mechanics which refers to the study of rigid body in

motion without reference to the force that causes the motion?

A. Statics

B. Kinetics

C. Kinematics

D. Dynamics

4. What refers to the force that holds part of the rigid body together?

A. Natural force

B. External force

C. Internal force

D. Concentrated force

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5. What refers to a pair of equal, opposite and parallel forces?

A. Couple

B. Moment

C. Torque

D. All of the above

6. What is a concurrent force system?

A. All forces act at the same point.

B. All forces have the same line of action.

C. All forces are parallel with one another.

D. All forces are in the same plane.

7. When will a three-force member be considered in equilibrium?

A. When the sum of the two forces is equal to the third force.

B. When they are concurrent or parallel.

C. When they are coplanar.

D. All of the above

8. A build-in, fixed support has how many reactions and moment?

A. 1 reaction and 1 moment

B. 2 reactions and 1 moment

C. 1 reaction and 2 moments

D. 2 reactions and no moment

9. What is the science that describes and predicts the effect on bodies at rest or in motion

by forces acting on it?

A. Engineering Mechanics

B. Theory of Structures

C. Mechanics of Materials

D. Strength of Materials



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10. “The sum of individual moments about a point caused by multiple concurrent forces is

equal to the moment of the resultant force about the same point”. This statement is

known as ____.

21. Pappus proposition

B. D’ Alembert’s principle

C. Varignon’s theorem

D. Newton’s method

11. “Two forces acting on a particle may be replaced by a single force called resultant

which can be obtained by drawing diagonal of parallelogram, which has the sides equal to

the given forces”. This statement is known as _____.

A. Pappus Propositions

B. Principle of Transmissibility

C. Parallelogram Law

D. Varignon’s Theorem

12 The term 'Centroid' is

(A) The same as centre of gravity

(B) The point of suspension

(C) The point of application of the resultant of all the forces tending to cause a body to

rotate about a certain axis

(D) None of the above

13 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

14 Forces are called coplanar when all of them acting on body lie in

(A) One point

(B) One plane



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(C) Different planes

15 Centre of gravity of a solid cone lies on the axis at the height

(A) One fourth of the total height above base

(B) One third of the total height above base

(C) One-half of the total height above base

(D) Three eighth of the total height above the base

16 The resultant of two forces P and Q (such that P > Q) acting along the same straight

line, but in opposite direction, is given by

(A) P + Q

(B) P - Q

(C) P / Q

(D) Q / P

17 Which of the following statement is correct?

(A) The algebraic sum of the forces, constituting the couple is zero

(B) The algebraic sum of the forces, constituting the couple, about any point is the same

(C) A couple cannot be balanced by a single force but can be balanced only by a couple of

opposite

(D) All of the above

18 Three forces acting on a rigid body are represented in magnitude, direction and line of

action by the three sides of a triangle taken in order. The forces are equivalent to a couple

whose moment is equal to

(A) Area of the triangle

(B) Twice the area of the triangle

(C) Half the area of the triangle

(D) None of thes

19 A force acting on a body may

(A) Change its motion



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(B) Balance the other forces acting on it

(C) Retard its motion


20 Lami's theorem states that

(A) Three forces acting at a point will be in equilibrium

(B) Three forces acting at a point can be represented by a triangle, each side being

proportional to force

(C) If three forces acting upon a particle are represented in magnitude and direction by

the sides of a triangle, taken in order, they will be in equilibrium

(D) If three forces acting at a point are in equilibrium, each force is proportional to the

sine of the angle between the other two

21 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

22 The forces, which meet at one point and their lines of action also lie on the same plane,

are known as

(A) Coplanar concurrent forces

(B) Coplanar non-concurrent forces

(C) Non-coplanar concurrent forces

(D) Non-coplanar non-concurrent forces

23Pick up the incorrect statement from the following:

(A) The C.G. of a circle is at its centre

(B) The C.G. of a triangle is at the intersection of its medians



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(C) The C.G. of a rectangle is at the intersection of its diagonals

(D) The C.G. of a semicircle is at a distance of r/2 from the centre

24 If three forces acting in one plane upon a rigid body, keep it in equilibrium, then they must

either

(A) Meet in a point

(B) Be all parallel

(C) At least two of them must meet

(D) All the above are correct

25 The energy possessed by a body, for doing work by virtue of its position, is called

(A) Potential energy

(B) Kinetic energy

(C) Electrical energy

(D) Chemical energy

26 The centre of gravity of a uniform lamina lies at

(A) The centre of heavy portion

(B) The bottom surface

(C) The midpoint of its axis


27 The three forces of 100 N, 200 N and 300 N have their lines of action parallel to each other but

act in the opposite directions. These forces are known as

(A) Coplanar concurrent forces

(B) Coplanar non-concurrent forces

(C) Like parallel forces

(D) Unlike parallel forces

28 The necessary condition for forces to be in equilibrium is that these should be

(A) Coplanar

(B) Meet at one point

(C) Both (A) and (B) above



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(D) All be equal

29 Which of the following is a vector quantity?

(A) Energy

(B) Mass

(C) Momentum

(D) Angle

30 The moment of a force

(A) Is the turning effect produced by a force, on the body, on which it acts

(B) Is equal to the product of force acting on the body and the perpendicular distance of a point

and the line of action of the force

(C) Is equal to twice the area of the triangle, whose base is the line representing the force and

whose vertex is the point, about which the moment is taken


31 According to Newton's first law of motion,

(A) Everybody continues in its state of rest or of uniform motion, in a straight line, unless it is

acted upon by some external force

(B) The rate of change of momentum is directly proportional to the impressed force, and takes

place in the same direction, in which the force acts

(C) To every action, there is always an equal and opposite reaction


32 Which of the following is not a vector quantity?

(A) Weight

(B) Velocity

(C) Acceleration

(D) Force

33 D' Alembert's principle is used for

(A) Reducing the problem of kinetics to equivalent statics problem

(B) Determining stresses in the truss

(C) Stability of floating bodies



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(D) Designing safe structures

34 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


35 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

36 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

37 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

38 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



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39 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

40 The resultant of two forces P and Q acting at an angle θ is

(A) √(P² + Q² + 2PQ sinθ)

(B) √(P² + Q² + 2PQ cosθ)

(C) √(P² + Q² - 2PQ cosθ)

(D) √(P² + Q² - 2PQ tanθ)

41 Two non-collinear parallel equal forces acting in opposite direction

(A) Balance each other

(B) Constitute a moment

(C) Constitute a couple

(D) Constitute a moment of couple

42 The center of gravity of a triangle lies at the point of

(A) Concurrence of the medians

(B) Intersection of its altitudes

(C) Intersection of bisector of angles

(D) Intersection of diagonals

43 Which of the following are vector quantities?

(A) Angular displacement

(B) Angular velocity

(C) Angular acceleration

(D) All of these



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44 When trying to turn a key into a lock, following is applied

(A) Coplanar force

(B) Non-coplanar forces

(C) Moment

(D) Couple

45 Two coplanar couples having equal and opposite moments

(A) Balance each other

(B) Produce a couple and an unbalanced force

(C) Are equivalent

(D) Cannot balance each other

46 According to law of triangle of forces

(A) Three forces acting at a point will be in equilibrium

(B) Three forces acting at a point can be represented by a triangle, each side being proportional to

force

(C) If three forces acting upon a particle are represented in magnitude and direction by the sides

of a triangle, taken in order, they will be in equilibrium

(D) If three forces acting at a point are in equilibrium, each force is proportional to the sine of the

angle between the other two

47 A couple produces

(A) Translatory motion

(B) Rotational motion

(C) Combined translatory and rotational motion


48 The resolved part of the resultant of two forces inclined at an angle 'θ' in a given direction is

equal to

(A) The algebraic sum of the resolved parts of the forces in the given direction

(B) The sum of the resolved parts of the forces in the given direction

(C) The difference of the forces multiplied by the cosine of θ



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(D) The sum of the forces multiplied by the sine of θ

49 Varingon's theorem of moments states that if a number of coplanar forces acting on a particle

are in equilibrium, then

(A) Their algebraic sum is zero

(B) Their lines of action are at equal distances

(C) The algebraic sum of their moments about any point in their plane is zero

(D) The algebraic sum of their moments about any point is equal to the moment of their resultant

force about the same point

50 The bellow figure shows the two equal forces at right angles acting at a point. The value of

force ‘R’ acting along their bisector and in opposite

direction is

(A) P/2

(B) 2P

(C) √2 × P

(D) P/√2

51 The principle of transmissibility of forces states that, when a force acts upon a body, its effect

is

(A) Same at every point on its line of action

(B) Different at different points on its line of action

(C) Minimum, if it acts at the center of gravity of the body

(D) Maximum, if it acts at the center of gravity of the body

52 The resultant of two equal forces ‘P’ making an angle ‘θ’, is given by

(A) 2P sinθ/2

(B) 2P cosθ/2

(C) 2P tanθ/2

(D) 2P cotθ/2

53 The point, through which the whole weight of the body acts, irrespective of its position, is

known as

(A) Moment of inertia

(B) Center of gravity



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(C) Center of percussion

(D) Center of mass

55 The total momentum of a system of masses (i. e. moving bodies) in any one direction remains

constant, unless acted upon by an external force in that direction. This statement is called

(A) Newton's first law of motion

(B) Newton's second law of motion

(C) Principle of conservation of energy

(D) Principle of conservation of momentum

56 If the resultant of two equal forces has the same magnitude as either of the forces, then the

angle between the two forces is

(A) 30°

(B) 60

(C) 90°

(D) 120°

57 Consider the following statements:

1. Two couples in the same plane cane be added algebraically [IAS-2000]

2. Coplanar and concurrent forces are the ones which do neither lie in one plane nor

meet at a point

3. Non-concurrent forces are the ones which do nut meet at a point.

4. A single forces may be replaced by a force and couple.

Which of these statements are correct?

(a) 1, 2 and 4 (b) 2, 3 and 4 (c) 1, 2 and 3 (d) 1, 3 and 4

58 The bellow figure shows the three coplanar forces P, Q and R acting at a point O. If these forces

are in equilibrium, then

(A) P/sin β = Q/sin α = R/sin ɣ

(B) P/sin α = Q/sin β = R/sin ɣ

(C) P/sin ɣ = Q/sin α = R/sin β

(D) P/sin α = Q/sin ɣ = R/sin β



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59 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

60 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


-: a k gaikar (ankushgaikar.wordpress.com) · 2017. 1. 16. · objective test 1 engineering...

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