GATE'22 CE:- Daily Practice Quiz 20-Aug-2021

Quiz: Civil Engineering
Exam: GATE
Topic: Miscellaneous

Each question carries 2 marks
Negative marking: 1/3 mark
Time: 12 Minutes

Q1. For field rivets, the permissible stresses are reduced by what percentage?
(a) 10%
(b) 15%
(c) 25%
(d) 33 1/3%

Q2. The minimum strain at failure in tension steel having yield stress f_y = 415 MPa and Young’s Modulus E_S=200 GPa, as per limit state method of design, is
(a) 0.0025
(b) 0.0038
(c) 0.0045
(d) 0.0050

Q3. The principal strains at a point are + 800 × 10^(-6) cm/cm, + 400 × 10^(-6) cm/cm and -1200 × 10^(-6) cm/cm. The volumetric strain is equal to
(a) +1200×10^(-6) cm\/cm
(b) + 800 × 10^(-6) cm/cm
(c) -1200×10^(-6) cm\/cm
(d) zero

Q4. What is the true area (in acres), if the area calculated by a chain which is found to be 0.8 link too long is 100 acres?
(a) 100.8
(b) 99.2
(c) 98.4
(d) 101.6

Q5. As per the Lacey’s method for design of alluvial channels, identify the TRUE statements the following:
(a) Wetted perimeter increases with an increase in design discharge.
(b) Hydraulic radius increases with an increase in silt factor.
(c) Wetted perimeter decreases with an increase in design discharge.
(d) Wetted perimeter increases with an increase in silt factor.

Solutions

S1. Ans.(a)
Sol. As per IS 800 – 1984. For the field rivets, the permissible stress are decreased by 10%.

S2. Ans.(b)
Sol. Given,
fy=415
E_S=200 GPa
Minimum strain at failure as per IS 456 : 2000
=0.87fy/E_S +0.002
=(0.87×415)/(200×10^3 )+0.002
=0.0038

S3. Ans.(d)
Sol. Given, ϵ_x=+800×10^(-6) cm\/cm
ϵ_y=+400×10^(-6) cm\/cm
ϵ_z=-1200×10^(-6) cm\/cm
Volumetric strain =∆V/V=ϵ_x+ϵ_y+ϵ_z
=(800×10^(-6) )+(400×10^(-6) )+(-1200×10^(-6) )
=0

S4. Ans.(d)
Sol. Assume, length of chain = 30 m
True length of chain (l) = 30 m = 150 links
Wrong length of chain (l’) = 150.8 links
=150.8×0.20 (∵1 link=20 cm=0.20 m)
=30.16 m.
Measured area (A’) = 100 Acre
True area (A) = ?
(l)^2×A=(l^’ )^2×A^’
(30)^2×A=(30.16)^2×100
▭(A=101.06 Acre)

S5. Ans.(a)
Sol. As per Lacey’s, wetted perimeter P is given by-
▭(P=4.75√Q)
Hence, wetted perimeter increases with an increase in design discharge.