Quiz: Civil Engineering 23 March 2020

Quiz: Civil Engineering
Exam: UPSSSC-JE
Topic: Hydraulics & Fluid Mechanics

Each question carries 1 mark
Negative marking: 1/3 mark
Time: 10 Minutes

Q1.The relationship between atmospheric pressure (Patm), gauge pressure (Pgauge) and absolute pressure (Pabs) is given by :
(a) Patm = Pabs + Pgauge
(b) Pabs = Patm + Pgauge
(c) Patm = Pabs + Pgauge
(d) none of the above
L1Difficulty 3
QTags Hydraulics & Fluid Mechanics
QCereator Anubhav Gupta

Q2. Wind speed is measured by an instrument
(a) Reflectometer
(b) Planimeter
(c) Anemometer
(d) Speedometer
L1Difficulty 3
QTags Hydraulics & Fluid Mechanics
QCereator Anubhav Gupta

Q3. Viscosity of water in comparison to mercury is :
(a) Higher
(b) Lower
(c) Same
(d) Higher/Lower depending on Temperature
L1Difficulty 3
QTags Hydraulics & Fluid Mechanics
QCereator Anubhav Gupta

Q4. Dynamic viscosity of a fluid with specific gravity 1.3 is measured to be 0.0034 Ns/m² its kinematic viscosity, in m²/sec is :
(a) 2.6 × 10^(–6)
(b) 4.4 × 10^(–6)
(c) 5.8 × 10^(–6)
(d) 7.2 × 10^(–6)
L1Difficulty 3
QTags Hydraulics & Fluid Mechanics
QCereator Anubhav Gupta

Q5. Poise is unit of
(a) (Dyne-sec⁡ )/(cm^2 )
(b) (Dyne-cm)/sec⁡〖〗
(c) (Dyne-cm)/〖sec〗^2
(d) (Dyne-sec⁡ )/cm
L1Difficulty 3
QTags Hydraulics & Fluid Mechanics
QCereator Anubhav Gupta

Q6. The depth of centre of Pr. For a vertically immersed surface from the liquid surface given by :
(a) I_G/A_¯X – ¯X
(b) I_G/¯X – A_¯X
(c) A_¯X/I_G + ¯X
(d) I_G/A_¯X + ¯X
L1Difficulty 3
QTags Hydraulics & Fluid Mechanics
QCereator Anubhav Gupta

Q7. Which one of the following pressure unit represents the least pressure?
(a) Millibar
(b) mm of Hg
(c) N/mm²
(d) kgf/cm²
L1Difficulty 3
QTags Hydraulics & Fluid Mechanics
QCereator Anubhav Gupta

Q8. Atmospheric pressure is measured by _____ .
(a) Altimeter
(b) Piezometer
(c) Barometer
(d) Spectrometer
L1Difficulty 3
QTags Hydraulics & Fluid Mechanics
QCereator Anubhav Gupta

Q9.Hydraulic radius is :
(a) (Wetted perimeter)/(Cross-sectional Area)
(b) (Cross-sectional Area)/(Wetted perimeter)
(c) Radius of channel
(d) All of above
L1Difficulty 3
QTags Hydraulics & Fluid Mechanics
QCereator Anubhav Gupta

Q10. Spherical shape of droplets of mercury is due to
(a) high density
(b) high surface tension
(c) high adhesion
(d) Water
L1Difficulty 3
QTags Hydraulics & Fluid Mechanics
QCereator Anubhav Gupta

Solutions

S1. Ans.(b)
Sol: Pabs = Patm + Pgauge

S2. Ans.(c)

S3. Ans.(b)

S4. Ans.(a)
Sol. μ = 0.0034 Ns/m²
G = 1.3
γ = 3
γ = μ/ρ = μ/(Gγ_ω )
⇒ (0.0034 Ns/m^2 )/(1.3×1000 kg/m³)
⇒ 2.6 × 10^(–6) m²/sec.

S5. Ans.(a)

S6. Ans.(d)
Sol. ¯h = (I_G sin²θ)/(A¯X) + ¯X
For vertically θ = 90°
[¯h = (I_G sin²θ)/(A¯X) + ¯X]
S7. Ans.(a)
Sol. 1 millibar = 10^(–3) bar
= 10^(–3) × 10^5 N/m²
= 100 N/m²
1 mm of Hg = (1×13.6×1000×9.81)/1000
= 133.416 N/m²
1 N/mm² = 10^6 N/m²
1 kgf/cm² = (1×9.81 N)/10^(–4) = 9.81 × 10^4 N/m²

S8. Ans.(c)
Sol.
S9. Ans.(b)
Sol.
Hydraulic Radius = (C⁄s Area)/(Wetter Perimeter) ▭(R=A/P)
S10. Ans.(b)
Sol. due to the surface tension is in balance with the internal pressure and the droplet form into sphere which is the shape for minimum surface area.