Quiz: Civil Engineering

Exam: UPPSC-AE

Topic: Strength of Material

Each question carries 1 mark

Negative marking: 1/3 mark

Time: 10 Minutes

Q1. The stress level, below which a material has a high probability of not failing under reversal of stress, is known as

(a) elastic limit

(b) endurance limit

(c) proportional limit

(d) tolerance limit

L1Difficulty 2

QTags Strength of Material

QCereator Anubhav Gupta

Q2. A beam is structural member predominantly subjected to

(a) Transverse loads

(b) Axial forces

(c) Twisting moment

(d) None of these

L1Difficulty 2

QTags Strength of Material

QCereator Anubhav Gupta

Q3. The load at the free end of a uniform cantilever beam is increased, the failure will occur

(a) at the middle

(b) at the fixed end

(c) at the point of application of load

(d) any where in the span

L1Difficulty 2

QTags Strength of Material

QCereator Anubhav Gupta

Q4. Principal planes are planes of

(a) maximum shearing stress

(b) zero shearing stress

(c) shearing stress having a magnitude of 50% of principal stress

(d) will be maximum

L1Difficulty 2

QTags Strength of Material

QCereator Anubhav Gupta

Q5. Maximum shear strain occurs on

(a) Principal planes

(b) 45 deg. With principal planes

(c) 90 deg. With principal planes

(d) All of above

L1Difficulty 2

QTags Strength of Material

QCereator Anubhav Gupta

Q6. For a beam, the term M/EI is:

(a) Stress

(b) Rigidity

(c) Curvature

(d) Shear force

L1Difficulty 2

QTags Strength of Material

QCereator Anubhav Gupta

Q7. At any point of a beam, the section modulus may be obtained by dividing the moment of inertia of the section by …………

(a) depth of the section

(b) depth of the neutral axis

(c) maximum tensile stress at the section

(d) maximum compressive stress at the section

L1Difficulty 2

QTags Strength of Material

QCereator Anubhav Gupta

Q8. Find the tensile stress of a mild steel rod of 18mm diameter. Given: ultimate load = 9.0 ton.

(a) 0.03 Ton/sq.mm

(b) 0.02 Ton/sq.mm

(c) 0.05 Ton/sq.mm

(d) 0.06 Ton/sq.mm

L1Difficulty 2

QTags Strength of Material

QCereator Anubhav Gupta

Q9. The ratio of the theoretical critical buckling load for a column with fixed ends to that of another column with the same dimension and material, but with pinned ends is equal to

(a) 0.5

(b) 4.0

(c) 2.0

(d) 1.0

L1Difficulty 2

QTags Strength of Material

QCereator Anubhav Gupta

Q10. Rankines Gorden formula used to find out buckling load of column

(a) Long column

(b) Medium column

(c) Short column

(d) None of these

L1Difficulty 2

QTags Strength of Material

QCereator Anubhav Gupta

SOLUTION

S1. Ans.(b)

Sol. The stress which can be withstand for some infinite number of cycles without failure is called endurance limit. Endurance limit magnitude less then yield strength.

S2. Ans.(a)

Sol. The beam is a structure element that primarily resists loads applied laterally (transverse) to the beam axis.

S3. Ans.(b)

Sol. If the load at the free end of a cantilever beam is increased the failure will occure at the fixed end because due to increase of load moment resisted by fixed support is increased and when support moment reaction increased beyond it’s limit then failure occure.

S4. Ans.(b)

Sol. Infinite plane’s passes through a single point. Out of infinite plane’s three planes are mutually perpendicular to each other and having zero shear stress, that planes are called principal plane.

S5. Ans.(b)

Sol. Maxm shear strain occure on 45° with the principal planes.

S6. Ans.(c)

Sol. By Bending equation

M/I=σ/y=E/R

M/I=E/R

M/EI=1/R

Curvature = 1/R

S7. Ans.(b)

Sol.

Section Modulus (Z) = (Moment of Inertia (I))/(Depth of the neutral axis (y))

If we consider Rectangular section

Z= I/y=(bd^3/12)/(d/12)

Z= bd²/6

S8. Ans.(a)

Sol. Diameter = 18 mm

Ultimate load = 9.0 ton

Tensile stress = (9.0 ton)/(π/4×18²)

= 0.035 ton/mm²

S9. Ans.(b)

Sol. (i) Pcr=π²EI/Le²

Both end’s fixed

Le = L/2

Pcr_1=(π^2 EJ×4)/L² -(i)

(ii) both end’s pinned

Le= L

Pcr_2=π²EI/L² -(ii)

(Pcr_1)/(Pcr_2 )=((π^2 EI×4)/L^2 )/((π^2 EI)/L^2 )

= 4

S10. Ans.(b)

Sol. → Rankines Gorden formula used to find out buckling load of medium column.

→ Euler formula used for calculating buckling load of long column.