objective type questions.combined

8/6/2019 Objective Type Questions.combined

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OBJECTIVE TYPE QUESTIONS IN TOM AND

MOM

Prepared by prakash and premjith(Roll no 9&10)

10/11/2010


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OBJECTIVE TYPE QUESTIONS

THEORY OF MACHINES1. The locus of instantaneous centre of a moving body relative to a fixed body is known as

(a) space centrode (b) body centrode

(c) moving centrode (d) none of the above

2. Quick return mechanism is an inversion of

(a) four bar chain (b) single slider crank chain

(C) double slider crank chain (d) crossed slider crank chain

3. The sense of coriolis component is the same as that of the relative velocity vector V

rotated at

(a) 180 degrees in the direction opposite to the rotation of the link containing the path.(b) 45 degrees in the direction of rotation of the link containing the path.(c) 45 degrees in the direction opposite to the rotation of the link containing the path.(d) 90 degrees in the direction of rotation of the link containing the path.

4. The lower pair is

(a) closed pair (b) unclosed pair (c) point contact pair

(d) surface contact pair (e) both (a) and (b) (f) both (a) and (c)

5. In a kinematic chain, if the specification of one co-ordinate, or dimension or position of a

single link is sufficient to define the position of all other links, then the chain is called a

kinematic chain of

(a) Two degree of freedom (b) one degree of freedom

(c) Three degree of freedom (d) none of the above

6. The differential mechanism of an automobile is having

(a) one degrees of freedom (b) two degrees of freedom

(c) three degrees of freedom (d) zero degree of freedom


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7. The Ackermann steering gear is the inversion of a

(a) slider crank chain (b) four bar chain

(c) double slider crank chain (d) crossed slider crank chain

8. The total number of instantaneous centre of a mechanism having 8 links, is equal to

(a) 8 (b) 28 (c) 7 (d) 4

9. The coriolis component of acceleration exists only whenever a point

(a) Moves along a circular path (b) moves in straight line

(c) Moves along a straight line which has rotational motion (d) none of the above

10. The motion of a shaft in a circular hole is an example of

(a) In completely constrained motion (b) completely constrained motion

(c) Successfully constrained motion (d) none of the above

ANSWERS:

THEORY OF MACHINES

1. A 2. B 3.D 4.E 5.B 6.B 7.B 8.B 9.C 10.A


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ADVANCED MECHANICS OF SOLIDS

1. The principal stresses at a point in two dimensional stress system are 1 and 2 and

corresponding principal strains are 1 and 2. If E and denote Youngs modulus andPoissons ratio, respectively, then which one of the following is correct?

(a) =E 1 (b) =E[1 +2] / [1-2]

(c) = E[1 -2] / [1-2] (d) = E[1 -2]

2. A point in a two dimensional state of strain is subjected to pure shearing strain of

magnitude xy radians. Which one of the following is the maximum pure strain?

(a) xy (b) xy /(2)1/2

(c) xy/2 (d) 2 xy

3. What is the relationship between the linear elastic properties Youngs modulus (E),rigidity modulus (G) and bulk modulus (K)?

(a) 1/E =9/K + 3/G (b) 3/E =9/K+ 1/G

(c) 9/E= 3/K + 1/G (d) 9/E= 1/K + 3/G

4. Consider the following statements:

1. Two-dimensional stresses applied to a thin plate in its own plane represent the planestress condition.

2. Under plane stress condition, the strain in the direction perpendicular to the plane is

zero .3. Normal and shear stresses may occur simultaneously on a plane.

Which of the above statements is/are correct?

(a) 1 only (b) 1 and 2 (c) 2 and 3 (d) 1 and 3


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5. In a strained material one of the principal stresses in twice the other. The maximum shear

stress in the same case is max . Then, what is the value of the maximum principal stress?

(a) max (b) 2 max (c ) 4 max (d)8 max

6. In a strained material, normal stresses on two mutually perpendicular planes are x and y

(both alike) accompanied by a shear stressxy . One of the principal stresses will be zero, onlyif

(a) xy = (xxy)/2 (b) xy= (xxy)

(c) xy = (xxy)1/2 (d) xy= (x2xy2)1/2

7. If the ratio G/E (G= Rigidity modulus, E=Youngs modulus of elasticity) is 0.4, then whatis the value of the Poisson ratio?

(a) 0.20 (b) 0.25 (c) 0.30 (d) 0.33

8. E, G, K and m represent the elastic modulus, shear modulus, bulk modulus and Poissonsratio respectively of a linearly elastic, isotropic and homogeneous material. To express thestress strain relations completely for this material, atleast

(a)E, G and m must be known (b) E, K and m must be known

(c) any two of the four must be known (d) all the four must be known

9. If nn, ny, nz are the direction cosines of normal to the plane which is equally inclined to thethree axes then determine nx.

(a)1 (b) 1/3 (c ) 1/3 (d) 3/2


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10. The state of strain at a point is given by the following array of terms

9 6 3

6 5 2

3 2 4

Determine xy(a) 12 (b) 6 (c) 3 (d) 8

ANSWERS:

ADVANCED MECHANICS OF SOLIDS

1. (b) =E[1 +2] / [1-2]

1= (1/E)-( 2 /E)

2 =(2/E)-( 1 /E)

solving the 2 equations we get

=E[1 +2] / [1-2]

2. (c) xy/2 ,pure shearing strain of magnitude = xy

Maximum principal strain= xy/2

3. (d) 9/E= 1/K + 3/G

E=2G(1+)

E=3K(1-2 )

Solving these two we get

9/E= 1/K + 3/G

4. (d)


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5. (c) 4 max

max =(1 2)/2 = (1( 1/2))/2

=4 max

6. (c) xy = (xxy)1/2

(x+y)/2 + (((x+y)/2)2 + xy2) =0

xy2= x y

xy = (xxy)1/2

7. (b) 0.25

G/E= 1/2(1+ ) = 0.4

= 0.25

8. (c) any two of the four must be known

9. (c ) 1/3

10. (a) 12

objective type questions.combined

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