Quiz: Civil Engineering 30 June 2021

Quiz: Civil Engineering
Exam: DFCCIL
Topic: Miscellaneous

Each question carries 1 mark
Negative marking: 1/4 mark
Time: 10 Minutes

Q1. A soil has percentage air voids of the order of 30%. It has a porosity of 0.4 the air content of that soil shall be:
(a) 0.75
(b) 0.12
(c) 1.33
(d) 0.70

Q2. If a retention of 0.75 m is obtained from a tachometer on a vertical staff, then the horizontal distance between the tacheometer and staff station is?
(a) 75 m
(b) 25 m
(c) 7.5 m
(d) 50 m

Q3. A gradient of 1° represents a rise or fall of 1m in a horizontal distance of
(a) 57.3 m
(b) 44.7 m
(c) 63.3 m
(d) 68.7 m

Q4. If the pH of the water is more than 8.5, then which of the following chloramines will be
(a) Only monochloramine
(b) Only dichloramine
(c) Only trichloramine
(d) Both monochloramine and dichloramine

Q5. The point of contraflexure is the point where:
(a) bending moment changes sign
(b) bending moment is maximum
(c) bending moment is minimum
(d) shear force is zero

Q6. A circular shaft can transmit a torque of 5 kNm. If the torque is reduce to 4 kNm, then the maximum value of bending moment that can be applied to the shaft is
(a) 1 kNm
(b) 2 kNm
(c) 3 kNm
(d) 4 kNm

Q7. The final deflection due to all loads including the effects of temperature, creep and shrinkage and measured from as–cast level of supports of floors, roofs and all other horizontal members should not exceed …………..
(a) Span/350
(b) Span/300
(c) Span/250
(d) Span/200

Q8. The process of proper and accurate measurement of concrete ingredients for uniformity of proportion is known as. …………..
(a) Batching
(b) Grading
(c) Mixing
(d) None of these

Q9. The maximum allowable deflection in roof purlins is:
(a) 10 mm
(b) L/200
(c) L/325
(d) L/400

Q10. The degree of indeterminacy of the beam given above is

(a) zero
(b) one
(c) two
(d) three

Solutions

S1. Ans.(a)
Sol. percentage air void (η_a ) = 30%
Porosity (n) = 0.4
Air content (a_c) = ?
η_a = na_c
0.30 = 0.4 × a_c
▭(a_c=0.75)

S2. Ans.(a)
Sol. Staff intercept (s) = 0.75 meter
▭(D=kS+C)
Multiplying constant (k) = 100
Additive constant (c) = 0
D= 100×0.75+0
▭(D=75 metre)

S3. Ans.(a)
Sol. Let horizontal distance = D
Slope = 1°
Rise/fall = 1m

Tan 1° = 1/D
D = 1/(Tan 1° )
= 1/0.017455
D = 57.3 m

S4. Ans.(a)
Sol.

pH value	Chloramine
> 7	Monochloramine
4-7	Dichloramine
1-3	Tri-chloramine

S5. Ans.(a)
Sol. Point of contraflexure (POC) is the point where bending moment changes sign.
→ When function changes from concave to convex or vice versa that point is called point of inflection.

S6. Ans.(c)
Sol. T_e=5 KN.m.
T= 4 KN.m
M= ?
Equivalent Torque (Te) = √(T^2+M²)
5=√(4^2+M²)
M= 3 KN.m

S7. Ans.(c)
Sol. deflection after partition (final deflection) = Spon/250
Deflection before partition = Spon/350

S8. Ans.(a)
Sol. Batching→ It is the process of proper and accurate measurement of concrete ingredients. It is either done by mass or volume batching.

S9. Ans.(b)
Sol. The maximum allowable deflection in roof purlins is L/200. In design of purlin, the depth of angle section should not be less than L/45 and the width should not be less than L/60.

S10. Ans.(b)
Sol.
No.of external reactions(r_e )=5
Internal hinged reactions (r_r )=1
Degree of static indeterminacy(D_s)=r_e-3-r_r
=5-3-1
▭(D_s=1 )

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