Deck 4: Mechanics of Materials: Understanding Stress, Strain, and Energy Storage in Materials

Question 1

The total strain energy stored in a body is termed as

A)resilience
B)proof resilience
C)modulus of resilience
D)toughness

Answer 1

resilience

Question 2

Proof resilience per material is known as

A)resilience
B)proof resilience
C)modulus of resilience
D)toughness

Answer 2

modulus of resilience

Question 3

The stress induced in a body due to suddenly applied load compared to when it is applied gradually is

A)same
B)half
C)two times
D)four times

Answer 3

two times

Question 4

strain energy stored in a body due to suddenly applied load compared to when it is applied gradually is

A)same
B)twice
C)four times
D)eight times

Question 5

During a tensile test on a specimen of 1 cm cross-section, maximum load observed was 8 tonnes and area of cross-section at neck was 0.5 cm². Ultimate tensile strength of specimen is

A)4 tonnes/cm²
B)8 tonnes/cm²
C)16 tonnes/cm²
D)22 tonnes/cm²

Question 6

Tensile strength of a material is obtained by dividing the maximum load during the test by the

A)area at the time of fracture
B)original cross-sectional area
C)average of (a) and (b)
D)minimum area after fracture

Question 7

An axial pull of 50 KN is suddenly applied to a steel bar 2 m long and 1000 mm² in cross-section. If modulus of elasticity is 200 GPa, find strain energy stored in the bar

A)10,000 N.mm
B)20,000 N.mm
C)25,000 N.mm
D)50,000 N.mm

Question 8

A 10 m long mild steel rail section is fixed at 300 K temperature. If temperature increases by 60 K, find stress in rail section if ends are not yielded. Coefficient of thermal expansion is 12×10^-6/K.

A)72 N/mm²
B)144 N/mm²
C)120 N/mm²
D)240 N/mm²

Question 9

The ultimate shear stress of a mild steel plate of 10 mm thickness is 350 N/mm². Calculate the diameter of the hole that can be punched to it without exceeding a compressive stress of 700 N/mm².

A)10 mm
B)20 mm
C)7 mm
D)35 mm

Question 10

A bar 2 m long and 20 mm diameter is subjected to an axial pull of 125.6 KN. Due to this load, length increases by 4 mm and diameter reduce by 0.012 mm. Find Poison?s ratio.

A)0.2
B)0.25
C)0.3
D)0.35

Question 11

A composite section of R.C.C. column 300mm×300mm in section having 20mm diameter 4 bars, one at each corner. Strength of concrete is 5 N/mm² and modular ratio Es/Ec=9. Calculate load taken by column.

A)150 KN
B)200 KN
C)400 KN
D)500 KN

Question 12

The moment of inertia of a triangular section of base 3 unit and height 2 unit, about an axis passing through its base is .

A)6
B)9
C)8
D)2

Question 13

Moment of inertia of a square of side 1 unit about an axis through its center of gravity, is .

A)1
B)1/12
C)1/3
D)1/4

Question 14

The axis about which moment of area is taken is known as .

A)Axis of area
B)Axis of moment
C)Axis of reference
D)Axis of rotation

Question 15

What is the formula of theorem of parallel axis?

A)Iab = Ig + ah
B)Iab = ah² + Ig
C)Iab = Ig - ah²
D)Izz = Iyy + Ixx

Question 16

Moment of inertia of a circular section of 2 cm diameter, about an axis through its centre of gravity, is .

A)?/64
B)?/4
C)?/16
D)?/2

Question 17

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 above

Question 18

What is the unit of moment of inertia?

A)mm
B)mm²
C)mm³
D)mm⁴

Question 19

What is the unit of Radius of gyration?

A)mm
B)mm²
C)mm³
D)mm⁴

Question 20

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

Question 21

What will be the radius of gyration of a circular plate of diameter 10cm?

A)1.5cm
B)2.0cm
C)2.5cm
D)3.0cm

Question 22

Moment of inertia of any section about an axis passing through its C.G is

A)Maximum
B)Minimum
C)Depends upon the dimensions of the section
D)Depends upon the shape of the section

Question 23

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
D)3