Civil Engineering
GATE CE purpose:exam-prep PYQs
Build your understanding with focused practice from past exam papers.
Questions 121–130 of 1300. Imported answers require independent review unless marked reviewed.
Question 61
Open questionCENAT2 marksNeeds review
In a bitumen mix, the percentage by weight of coarse aggregate, fine aggregate, filler, and bituminous binder is 58, 25, 12, and 5, respectively. The corresponding specific gravity of these materials is 2.68, 2.45, 2.42, and 1.15. The bulk specific gravity of the mix is 2.2.
The Void Filled with Bitumen (VFB, in percentage) is __________ (rounded off to the nearest integer).
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Open questionCENAT2 marksNeeds review
A vertical curve is formed by a descending gradient of 1 in 40 meeting an ascending gradient of 1 in 50. Consider the following:
Stopping Sight Distance (SSD) = 90 m
Height of headlight of a vehicle above the road surface = 0.75 m
Headlight beam angle with respect to the longitudinal axis of the vehicle = 1.2°
Based on the sight distance criteria, the design length (in m) of the vertical curve is ______ (rounded off to the nearest integer).
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Open questionCENAT2 marksNeeds review
The following consecutive readings (in m) were taken with a dumpy level and a levelling staff at a common interval of 20 m:
0.35; 1.030; 1.925; 2.825; 3.730; 4.850; 1.045; 2.05; 3.30; 4.580
The dumpy level was shifted after taking the sixth reading.
The gradient (in %) of the ground between the first and the last location of the reading is _____ (in integer).
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Open questionCENAT2 marksNeeds review
Interior angles measured at the locations of a closed traverse ABCDA are given in table below.
Location | Interior angle |
|---|---|
A | 71° 1′ 40″ |
B | 104° 54′ 23″ |
C | 107° 4′ 10″ |
D | 76° 20′ 42″ |
The total error in the measured angles (in degrees) is ____________ (rounded off to three decimal places).
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You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 63
Open questionCENAT2 marksNeeds review
An Activated Sludge Process (ASP) has an inlet wastewater flowrate of 2000 m³/day with a Biochemical Oxygen Demand (BOD) concentration of 250 mg/l. It produces treated wastewater containing 20 mg/l BOD. The aeration tank has a working volume of 600 m³ and a biomass concentration of 3000 mg/l. Biological Sludge Residence Time (BSRT) of the system is 6 days. The influent wastewater and the treated effluent from the system have negligible concentrations of biomass. The sludge recycle line from the bottom of the Secondary Sedimentation Tank (SST) to the inlet of the aeration tank has a flowrate of 600 m³/day.
To maintain equilibrium, the flowrate (in m³/day) of sludge that is to be wasted from the system is _____ (in integer).
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Open questionCENAT2 marksNeeds review
The analysis of major cations and anions in a water sample collected from a city’s water supply is given below. Ions present in minor concentrations are not given.
Anions | | | | |
|---|---|---|---|---|
Concentration (mM) | 1.5 | 0.5 | 1.0 | 0.01 |
Cations | | | | |
Concentration (mM) | 2 | 0.5 | 0.25 | 0.02 |
(in %) present in the total free chlorine in the water is ____ (rounded off to the nearest integer).Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 64
Open questionCENAT2 marksNeeds review
The intensity-duration relationship for a rainfall on a rectangular plot ABCD of area 7 ha (1 ha = 10⁴ m²) can be modeled by the following equation:
where I is rainfall intensity (in cm/h), and t is the duration (in minutes) of rainfall. The average runoff coefficient over the area is 0.60. The time of entry (in minutes) to the outfall from the corners A, B, C, and D are 10, 20, 15 and 25, respectively.
The design flowrate (in m³/h) of the storm-sewer at the outfall is _____ (in integer).
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Open questionCENAT2 marksNeeds review
Anaerobic bacteria are being utilized for the destruction of biodegradable organic content of wastewater measured in terms of Chemical Oxygen Demand (COD). The yield coefficient (Y) is 0.06 gram Volatile Suspended Solids (VSS) per gram of COD. Bacterial biomass forms the sludge during the process. The proximate chemical formula of anaerobic bacteria is C₆H₇NO₂.
The COD (in %) converted into bacterial biomass is ______ (rounded off to the nearest integer).
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Open questionCENAT2 marksNeeds review
The maximum demand at a water purification plant has been estimated as 12 million litres per day. For the raw supplies, a rectangular sedimentation tank is to be designed with mechanical sludge removal arrangement. Consider depth of the tank as 4 m, detention period as 6 hours, and velocity of flow as 0.003 m/s.
The width (in m) of the detention tank is ________ (rounded off to two decimal places).
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Open questionCENAT2 marksNeeds review
In an industry, a cyclone collector with 80 % efficiency is installed for air purification, followed by an electrostatic precipitator with 50 % efficiency. The concentration of particles entering the cyclone collector is 10 mg/m³.
The concentration (in mg/m³) of particles exiting the precipitator is ______ (rounded off to two decimal places).
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