1 ) The accuracy of the solution to a problem depends upon two items : - (1) the accuracy of the given data and (2) the accuracy of the computations performed . Single choice. A ) True , B ) False ,

1 ) The accuracy of the solution to a problem depends upon two items : -

(1)  the accuracy of the given data and

(2) the accuracy of the computations performed .  Single choice.

A )  True  ,

B )  False ,

Correct answers : -   A )  True ,

 

2 )  Most of the bodies considered in elementary mechanics are assumed to be rigid .  We define a rigid body as one that does not deform .   

A )  True ,

B )  False ,

Correct answers : -    A )  True ,

 

3 )  Two important concepts associated with the effect of a force on a rigid body are the moment of a force about a point and the moment of a force about an axis .

A )  True ,

B )  False ,

Correct answers : -   A )  True ,

 

4 )  we can replace any system of forces acting on a rigid body by an equivalent system consisting of one force acting at a given point and one couple .  This basic combination is called a force - couple system .

A )  True ,

B )  False ,

Correct answers : -   A )  True ,

 

5 )  Forces acting on rigid bodies can be separated into two groups : -

(1) external forces and

(2) internal forces .

A )  True  ,

B )  False ,

Correct answers : -   A )  True  ,

 

6 )  External forces are exerted by other bodies on the rigid body under consideration .

A )  True ,

B )  False ,

Correct answers : -  A )  True ,

 

7  )  Internal forces hold together the particles forming the rigid body .

A )  True ,

B )  False ,

Correct answers : -   A )  True ,

 

8 )   Mixed Triple Product of Three Vectors  S P and Q can be written as : -

A )   S . (P X Q)  ,

B )   S x (P . Q) ,

C )   S x (P x Q) ,

D )   S . (P . Q)  ,

Correct answers : -  A )   S . (P X Q)  ,

 

9 )  Scalar Product of Two Vectors : -

A )   P . Q = PQ cos θ  ,

B )   P . Q = PQ sin θ  ,

C )   P x Q = PQ sin θ  ,

D )   P x Q = PQ sin θ ,

Correct answers : -    A )   P . Q = PQ cos θ  ,

 

10 )  Parallel forces have parallel lines of action and may or may not have the same sense( direction ) .

A )  True ,

B )  False ,

Correct answers : -   A )  True ,

 

11 )  Coplanar forces act in the same plane .

A )  True  ,

B )  False  ,

Correct answers : -   A )  True  ,

 

12 )  Concurrent forces act at the same point .

A )  True  ,

B )  False  ,

Correct answers : -  A )  True  ,

 

13 )  Any force F acting on a rigid body can be moved to an arbitrary point O provided that we add a couple whose moment is equal to the moment of F about O .

A )  True ,

B )  False ,

Correct answers : -  A )  True ,

 

14 )  We can reduce any system of forces, no matter how complex they are , to an equivalent force-couple system acting at a given point O .

A )  True  ,

B )  False  ,

Correct answers : -   A )  True  ,

 

15 )  Two systems of forces are equivalent if they can be reduced to the same force - couple system at a given point O .

A )  True  ,

B )   False ,

Correct answers : -  A )  True  ,

 

16 ) Two systems of forces are equivalent if they tend to impart to the rigid body (1) the same translation in the x , y , and z directions , respectively , and (2) the same rotation about the x , y , and z axes , respectively .

A )  True ,

B )  False ,

Correct answers : -  A )  True ,

 

17 )  In general , when two systems of vectors satisfy such that when their force resultants and their moment resultants about an arbitrary point O are respectively equal , the two systems are said to be equipollent .

A )   True ,

B )   False ,

Correct answers : - A )   True ,

 

18 ) If two systems of forces acting on a rigid body are equipollent , they are also equivalent .

A )  True  ,

B )  False ,

Correct answers : -  A )  True  ,

 

19 )  Moment of a Force about an Axis line OL is given as …………….. ,

A )  M(OL) = λ . M(O)  ,

B )  M(OL) = λ x M(O) ,

Correct answers : -  A )  M(OL) = λ . M(O)  ,

 

20 ) Projection of a Vector on an Axis OL is given as ………….. ,

A )  P(OL) = P. λ(OL)  ,

B )  P(OL) = P x λ(OL) ,

Correct answers : -   A )  P(OL) = P. λ(OL)  ,

 

21 )  Forces are called concurrent when their lines of action meet in …………. ,

A )  plane ,

B )  two points ,

C )  one point ,

Correct answers : -  C )  one point ,

 

22 )  Forces are called coplanar when all of them acting on body lie in ……….. ,

A )  one point ,

B )  one plane ,

C )  different planes ,

Correct answers : -   B )  one plane ,

 

23 )  Effect of a force on a body depends upon …………… ,

A )  all of the above ,

B )  direction ,

C )  position or line of action ,

D )  magnitude ,

Correct answers : -  A )  all of the above ,

 

24 ) When trying to turn a key into a lock , the following is applied .

A )  coplanar force ,

B )  couple ,

C )  lever ,

Correct answers : -   B )  couple ,

 

25 )  According to the principle of transmissibility of forces , the effect of a force upon a body is ……………… ,

A )  maximum when it acts at the centre of gravity of a body ,

B )  the same at every point in its line of action ,

C )  different at different points in its line of action ,

Correct answers : -   B )  the same at every point in its line of action ,

 

26 )  Which of the following is a vector quantity ?

A )  Moment about a point ,

B )  Energy of system ,

C )  Moment about a line ,

Correct answers : -  A )  Moment about a point ,

 

27 )  A number of forces acting at a point will be in equilibrium if …………………. ,

A )  sum of resolved components is zero ,

B )  their total sum is non zero ,

C )  moment of forces is non zero ,

Correct answers : -   A )  sum of resolved components is zero ,

 

28 )  According to the principle of moments ……. ,

A )  the algebraic sum of the moments of any two forces about any point is equal to moment of their resultant about the same point ,

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 )  if a system of coplanar forces is in equilibrium , then their algebraic sum is zero .

 Correct answers : -   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 .

 

29 ) According to the law of triangle of forces ……. ,

A )  the lines of action of these forces meet in a point ,

B )  if three forces acting at a point they will be in equilibrium ,

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 .

Correct answers : -    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 .

 

30 )  Which of the following is a vector quantity ?

A )  Force ,

B )  Energy ,

C )  Mass ,

Correct answers : -   A )  Force ,

 

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