Statics and Strength of Materials: Master Forces and Stresses in Mechanical Parts

Question 1

A force of 100 N is applied to a steel rod with a cross-sectional area of 5 mm². Calculate the stress experienced by the rod.

Accepted Answer

15.9 MPa

Answer

20 MPa

Answer

25 MPa

Answer

30 MPa

Question 2

In the International System of Units (SI), the fundamental unit of force is the:

Accepted Answer

Newton (N)

Answer

Pascal (Pa)

Answer

Joule (J)

Answer

Kilogram (kg)

Question 3

Which of the following is NOT a type of force that can act on a structural element?

Accepted Answer

Centrifugal force

Answer

Shear

Answer

Tension

Answer

Compression

Question 4

Which of the following materials is known for its high compressive strength?

Accepted Answer

Concrete

Answer

Steel

Answer

Wood

Question 5

The formula for shear stress (τ) in a circular shaft subjected to torque (T) is:

Accepted Answer

τ = (16 * T) / (π * d^3)

Answer

τ = (8 * T) / (π * d^3)

Answer

τ = (2 * T) / (π * d^3)

Answer

τ = (4 * T) / (π * d^3)

Question 6

Which of the following is NOT a factor that affects the strength of a material?

Accepted Answer

Density

Answer

Alloying

Answer

Heat treatment

Answer

Grain size

Question 7

Which of the following is a physical quantity that has only magnitude and no direction?

Accepted Answer

Mass

Answer

Velocity

Answer

Displacement

Answer

Acceleration

Question 8

A force of 100 Newtons (N) is applied to an object at an angle of 30 degrees to the horizontal. What is the horizontal component of this force?

Accepted Answer

86.6 N

Answer

50 N

Answer

100 N

Answer

173.2 N

Question 9

A beam of length 'L' is supported at both ends. A point load 'P' is applied at the center of the beam. What is the maximum bending stress experienced by the beam?

Accepted Answer

3PL/2bh^2

Answer

PL/4bh^2

Answer

PL/8bh^2

Answer

PL/2bh

Question 10

A shaft with a diameter of 20 mm is subjected to a torque of 200 Nm. What is the maximum shear stress experienced within the shaft?

Accepted Answer

50 MPa

Answer

100 MPa

Answer

75 MPa

Answer

25 MPa

Question 11

Among the following materials, which one generally exhibits the highest tensile strength?

Accepted Answer

Steel

Answer

Concrete

Answer

Aluminum

Answer

Wood

Question 12

A column with a length 'L' is subjected to a compressive load 'P'. What is the formula for the critical buckling load of this column?

Accepted Answer

P = (π^2EI)/(4L^2)

Answer

P = (2π^2EI)/(4L^2)

Answer

P = (EI)/(4L^2)

Answer

P = (2EI)/(4L^2)

Question 13

Which of the following stress states involves both normal and shear stresses acting on a point?

Accepted Answer

Biaxial stress

Answer

Plane stress

Answer

Uniaxial stress

Answer

Triaxial stress

Question 14

A solid circular shaft is subjected to a pure torque. What is the shape of the shear stress distribution across the shaft's cross-section?

Accepted Answer

Parabolic

Answer

Uniform

Answer

Linear

Question 15

Which failure criterion is commonly used to predict the failure of brittle materials under stress?

Accepted Answer

Maximum principal stress criterion

Answer

Von Mises criterion

Answer

Tresca criterion

Answer

Maximum shear stress criterion

Question 16

A thin-walled pressure vessel is subjected to internal pressure 'p'.  What is the formula for the hoop stress experienced in the vessel?

Accepted Answer

pR/t

Answer

pR^2/t

Answer

2pR/t

Question 17

A steel bar with a cross-sectional area of 250 mm² is subjected to a tensile force of 50 kN. Calculate the stress in the bar.

Accepted Answer

200 MPa

Answer

100 MPa

Answer

50 MPa

Answer

250 MPa

Question 18

A simply supported beam carries a uniformly distributed load. Where does the maximum bending moment occur?

Accepted Answer

At the center of the beam

Answer

One-third of the span from the supports

Answer

At the supports

Answer

At a point one-quarter of the span from the supports

Question 19

A solid circular shaft with a diameter of 20 mm is subjected to a torque of 100 Nm. Calculate the shear stress in the shaft.

Accepted Answer

79.6 MPa

Answer

39.8 MPa

Answer

31.8 MPa

Answer

159.2 MPa

Question 20

Which of the following is NOT a type of stress?

Accepted Answer

Shear stress

Answer

Tensile stress

Answer

Compressive stress

Answer

Normal stress

Question 21

The modulus of elasticity is a material property that relates:

Accepted Answer

Stress to strain

Answer

Force to stress

Answer

Strain to displacement

Answer

Force to displacement

Question 22

A cantilever beam is fixed at one end and free at the other. Where does the maximum deflection occur?

Accepted Answer

At the free end

Answer

At the middle of the beam

Answer

One-third of the span from the fixed end

Answer

At the fixed end

Question 23

In engineering design, what is the purpose of a factor of safety?

Accepted Answer

To account for uncertainties in material properties and loading conditions

Answer

To increase the weight of the structure

Answer

To ensure the structure is aesthetically pleasing

Answer

To reduce the cost of materials

Question 24

Which of the following is a common method for analyzing indeterminate structures?

Accepted Answer

The method of superposition

Answer

The method of virtual work

Answer

The method of sections

Answer

The method of joints

Question 25

The moment of inertia of a rectangular cross-section about its centroidal axis is proportional to:

Accepted Answer

The cube of its height

Answer

The height itself

Answer

The width of the cross-section

Answer

The square of its height

Question 26

A thin-walled pressure vessel is subjected to an internal pressure. How does the hoop stress in the vessel relate to the longitudinal stress?

Accepted Answer

The hoop stress is twice the longitudinal stress

Answer

The hoop stress is four times the longitudinal stress

Answer

The hoop stress is half the longitudinal stress

Answer

The hoop stress is equal to the longitudinal stress