ENGG. Mechanics MCQ UNIT-III hvvhjkih PDF

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Mechanics (Greek: μηχανική) is the area of physics concerned with the motions of physical objects, more specifically the relationships among force, matter, and motion.[1] Forces applied to objects result in displacements, or changes of an object's position relative to its environment. This branch of...

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DEPARTMENT OF MECHANICAL ENGINEERING MODEL MCQ PAPER ENGINEERING MECHANICS (KME 402) UNIT – III (Centroid and Moment of Inertia) Q. No. 1

Question The point through which the whole weight of the body acts is called _____________ a) Inertial point b) Center of gravity c) Centroid

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d) Central point The point at which the total area of a plane figure is assumed to be concentrated is called ____________ a) Centroid b) Centre of gravity c) Central point

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d) Inertial point Where will be the centre of gravity of a uniform rod lies? a) At its end b) At its middle point c) At its centre of its cross sectional area d) Depends upon its material Where the center of gravity of a circle lies? a) At its centre b) Anywhere on its radius c) Anywhere on its circumference

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d) Anywhere on its diameter Where will be the center of gravity of the following section will lie in coordinates?

a) (6,3) b) (6,6) c) (6,1.5)

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d) (1.5,3) Where will be the centre of gravity of the T section shown in the figure?

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a) At 8.545cm b) At 6.5cm c) At 5cm d) At 9.25cm Where will be the center of gravity of the L-section shown in the figure?

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a) (1.28,2.64) b) (1.45,3.24) c) (1.64,3.28) d) (2.24,3.68) Where will be the center of gravity of the figure shown?

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a) (3.45,4.52) b) (3.59,7.42) c) (3.66,8.84) d) (3.88,8.88) The centre of gravity of a plane laminate will not be at its geometrical centre if it is a A. Circle B. Equilateral triangle C. Rectangle D. Right angled triangle

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Centre of gravity of a thin hollow cone lies on the axis of symmetry at a height of A. One-half of the total height above base B. One-third of the total height above base C. One-forth of the total height above base D. None of these

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The centre of gravity of a quadrant of a circle lies along its central radius at a distance of A. 0.2 R B. 0.3 R C. 0.4 R D. 0.6 R

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The centre of gravity of a right circular cone lies on its axis of symmetry at a height of A. h / 2 B. h / 3 C. h / 4 D. h / 5

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Q: Moment of inertia is the A. Second moment of area B. Second moment of mass C. Second moment of force

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D. All of these What is the formula of radius of gyration? a) k2 = I/A b) k2 = I2/A c) k2 = I2/A2 d) k2 = (I/A)1/2 What is the formula of theorem of perpendicular axis? a) Izz = Ixx – Iyy b) Izz = Ixx + Ah2 c) Izz – Ixx = Iyy d) None of the mentioned What is the formula of theorem of parallel axis? a) IAD = IG + Ah b) IAB = Ah2 + IG c) IAB = IG – Ah2 d) IAB = IG + Ixx What is the unit of radius of gyration? a) m4 b) m c) N d) m2 What will be the the radius of gyration of a circular plate of diameter 10cm? a) 1.5cm b) 2.0cm c) 2.5cm d) 3cm Moment of inertia of a circular section about an axis perpendicular to the section is a)πd³/16 b)πd³/32 c)πd⁴/32 d)πd⁴/64

20 The moment of inertia of a square of side a about its base is a)a⁴/3 b)a⁴/12 c)a³/3

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d)a⁴/16 Mass moment of inertia of a thin rod about its one end is ................the mass moment of inertia of the same rod about its mid point a)Same as b)Twice c)Thrice d)Four times Moment of Inertia of a solid sphere of mass m and radius r is

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a)2mr²/3 b)2mr²/5 c)mr² d)mr²/2 The unit of moment of inertia of an area, A. kg/m B. kg/m2 C. m4 D. m3

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Polar moment of inertia is A. Same as moment of inertia B. Applicable to masses whereas moment of inertia is applicable to area only C. The moment of inertia for an area relative to a linear or axis perpendicular to the plane of the area D. The moment of inertia for an area relative to a line or axis parallel to the centroidal axis

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Determine the radius of gyration ky of the parabolic area.

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A .

ky = 76.5 mm

B .

ky = 17.89 mm

C .

ky = 78.6 mm

D .

ky = 28.3 mm

The irregular area has a moment of inertia about the AA axis of 35 (106) mm4. If the total area is 12.0(103) mm2, determine the moment of inertia if the area about the BB axis. The DD axis passes through the centroid C of the area.

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A .

IBB = 5.00(106 ) mm4

B .

IBB = 17.00(106 ) mm4

C .

IBB = 16.80(106 ) mm4

D .

IBB = 55.4(106 ) mm4

The Figure shows cross-section of a beam subjected to bending. The area moment of inertia (inmm4)(inmm4) of this cross-section about its base is _________ .

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A. 1873.08 B. 1872.1 C. 1877 D. 1882.63 The radius of gyration of a ring of radius R about an axis through its centre and perpendicular to its plane is A. R / √2 B. R C. R/2

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D. 5 R / √2 Moment of inertia of a hollow circular section, as shown in the below figure about Xaxis, is

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(A) π/16 (D² - d²) (B) π/16 (D³ - d³) (C) π/32 (D⁴ - d⁴) (D) π/64 (D⁴ - d⁴) The moment of inertia of a solid cylinder of mass 'm', radius 'r' and length 'l' about the longitudinal axis or polar axis is (A) mr2/2 (B) mr2/4 (C) mr2/6 (D) mr2/8 The moment of inertia of a triangular section of base ‘b’ and height ‘h’ about an axis passing through its base is ……….. times the moment of inertia about an axis passing through its C.G. and parallel to the base (a) 9 (b) 4 (c) 2

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(d) 3 The moment of inertia of a body is always minimum with respect to its (a) Base (b) Centroidal axis (c) Vertical axis

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(d) Horizontal axis The moment of inertia of a circular section of base ‘b’ and height ‘h’ about an axis passing through its vertex and parallel to base is (a) bh3/12 (b) bh3/36 (c) bh3/3

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(d)bh4/4 The moment of inertia of a circular section about an axis perpendicular to the section is (a) πd4/32 (b) πd4/64 (c) πd4/4 (d) πd4/8

ANSWER KEY Q No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

Option B B A B B A A D B A D A B A A B A

Q No. 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34

Option A B B C B C C C A A B D C A C A B...