**Quiz: Civil Engineering**

**Exam: SSC-JE**

**Topic: Strength of Material**

**Each question carries 1 mark**

**Negative marking: 1/4 mark**

**Time: 10 Minutes**

Q1. In the case of pure bending, the beam will bend into an arc of a

(a) circle

(b) parabola

(c) ellipse

(d) hyperbola

Q2. E, G, K and ν represent the elastic modulus, shear modulus, bulk modulus and Poisson’s ratio respectively of a linearly elastic, isotropic and homogeneous material. To express the stress-strain relations completely for this material, at least

(a) E, G and ν must be known

(b) E, K and ν must be known

(c) any two of the four must be known

(d) All the four must be known

Q3. A beam fixed at both ends carries a uniformly distributed load on entire length. The ratio of bending moment at the support to the bending moment at mid span is given by

(a) 0.5

(b) 1.0

(c) 1.5

(d) 2.0

Q4. The ability of a material to absorb energy till the breaking or rupture takes place is known as

(a) Hardness

(b) Toughness

(c) Brittleness

(d) Softness

Q5. A simply supported beam is carrying distributed load of ‘zero’ intensity over one support to linearly varying nature of intensity ‘w’ over the other support. The shape of BMD will be

(a) linear

(b) parabolic

(c) cubical parabolic

(d) zero

Q6. The maximum dimension of a core section for a rectangular cross-section under eccentric loading on a column (b×d) is

(a) b/6

(b) d/6

(c) d/8

(d) b/3 and d/3

Q7. Malleability is the property of material which allows it to expand in:

(a) one direction without rapture

(b) two directions without rupture

(c) all directions without rupture

(d) NONE OF THESE

Q8. The stress in a beam is less if the section modulus is:

(a) high

(b) low

(c) zero

(d) NONE OF THESE

Q9. Which of the following statements is incorrect about Poisson’s ratio:

(a) can be negative

(b) can be zero

(c) can be positive

(d) can be gractional value

Q10. A point mohr circle on the negative side of Y-axis will be formed in case of:

(a) Hydrostatic tension

(b) Hydrostatic compression

(c) Pure shear

(d) Uniaxial compression

(Take tension as positive and compression as negative)

**SOLUTIONS**

S1. Ans.(a)

Sol. in case of pure bending, there will be no shear force in the member and the beam bend into an arc of a circle.

▭(M/I=E/R) (Consider equation of bending)

S2. Ans.(c)

Sol. Any two of the four must be known to express the stress-strain relations completely for the material.

Relation between E, G & K →

▭(E=9GK/(G+3K))

S3. Ans.(d)

Sol. A fixed beam carries UDL on entire length, then the bending moment

→ at supports =(WL^2)/12

→ at centre = (WL^2)/24

Hence ratio of bending moment at support to the bending moment at mid span is =

=((WL^2)/12)/((WL^2)/24)

=24/12

=2.0

S4. Ans.(b)

Sol. Toughness is the ability of material to absorb energy till breaking or rupture Point. It is also defined as total strain energy up to fracture.

S5. Ans.(c)

Sol. A simply supported beam is carrying distributed load of ‘zero’ intensity over one support to linearly varying nature of intensity ‘W’ over the other support then The shape of BMD will be cubic parabola.

S6. Ans.(d)

Sol. The maximum dimension of a core section for a rectangular cross-section under eccentric loading on a column (b × d) is b/3 or d/3. The shape of kern or core for rectangular and I – section is Rhombus.

S7. Ans.(c)

Sol. Malleability is the property of material by virtue of which it can be drawn into thin sheets after application of load i.e. can be expanded in any desired direction.

S8. Ans.(a)

Sol. from bending equation

M/I=σ/y

σ=M/I.y

σ=M/(I\/y)

▭(σ=M/Z)

▭( σ α 1/Z)

So, for σ to be less, Z should be more.

S9. Ans.(a)

Sol. The Poisson’s ratio is a property of material which can not be negative.

▭(0≤μ≤0.5)

Poisson’s ratio in elastic range = 0.3

Poisson’s ratio in plastic range = 0.5

S10. Ans.(b)

Sol. A point Mohr circle on the negative side of y-axis will be formed in case of hydrostatic compression or hydrostatic loading.