GATE MN topic:surface-environment PYQs & Answers

Home
GATE
Mining Engineering
Topics
topic:surface-environment

Attempt a question, record the concept and assumptions, then check the available answer. Rework mistakes after revising the relevant concepts. Topic tags can overlap; review the question context.

Questions 1–10 of 26. Imported answers require independent review unless marked reviewed.

Topic practice 26 questionsPage 1 of 3

Dust particles from a blasting operation rise up in the atmosphere to a height of 500 m. The viscosity of air is 1.80 × 10

kg m

. Assume the particles have quiescent settling (no turbulence) in atmosphere. Neglecting air density, the settling time, in days, of a dust particle of 2.5 μm diameter and 3600 kg m

density is ____________. (rounded off to two decimal places)

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

In a biochemical oxygen demand (BOD) test, 15 ml of wastewater sample was diluted with distilled water to completely fill a 300 ml BOD bottle and incubated at 20 °C for 5 days. The dissolved oxygen (DO) level before and after incubation are 9.2 mg liter

and 4.4 mg liter

, respectively. The BOD of the sample, in mg liter

, is ____________. (answer in integer)

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Average noise level at a working place is 80 dB(A) for the first 10 minutes and 60 dB(A) for the next 30 minutes. The energy equivalent continuous noise level at the place for the entire period of 40 minutes, in dB(A), is_____ (rounded off to 2 decimal places)

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

SO₂ is emitted at a rate of 20 kg/s from a 10 km × 10 km airshed in an industrial area. Wind blows at a speed of 4 m/s from one direction in that area. Radiation inversion restricts the mixing height to 1200 m. Neglect SO₂ concentration in the incoming air. Assuming emitted SO₂ to be conservative, the steady state SO₂ concentration in the airshed, in μg/m³, is____ (rounded off to 2 decimal places)

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

A wastewater sample has an ultimate BOD of 300 mg/L. BOD reaction rate constant is 0.22 per day at 20 °C. If the temperature coefficient is 1.05, the 5-day BOD at 25 °C, in mg/L, is ____ (rounded off to 2 decimal places)

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

A coal washery discharges 300 m

/day of contaminated water in a stream having a flow rate of 0.04 m

/s. The DO level of the stream and the contaminated water are 8.5 mg/L and 4 mg/L, respectively. Neglecting the impact of temperature, the resultant DO, in mg/L, of the stream just after mixing is ______. (round off up to 2 decimals)

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

The combined sound pressure level measured at a point in a production bench due to one dumper and one shovel is 95 dB(A). If the sound pressure level of shovel alone is 90 dB(A), the sound pressure level of the dumper alone, in dB(A), at the same point is________, (round off up to 2 decimals)

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Polluted air with particulate matters of diameter 50 μm enter with a horizontal velocity of 1.0 m/s at a height of 0.5 m from the bottom of a dry settling chamber. The density of the particle is 200 kg/m³ and dynamic viscosity of the air is 1.8 × 10⁻⁵ kg/m-s.

Assume streamline flow and the density of air is negligible as compared to particles and uniform horizontal velocity of 1.0 m/s of gas and particles within the chamber.

Considering particle setting follows Stoke’s law, the minimum length in m, of the chamber required for setting of the particle at its bottom is _____. (round off up to 2 decimals)

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

The reaction products of calcium hydroxide with acidic feruginous mine water are

Your answerChoose one option.

FeO, Ca⁺ and H⁺

FeO, CaO and H₂O

Fe₃, Ca³⁺ and OH⁻

Fe(OH)₃, Ca²⁺ and H₂O

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

In a sample of groundwater, the concentration of Ca²⁺ is 200 mg/l. The corresponding calcium carbonate hardness in mg/l is _____.

[rounded off to 1 decimal place]

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

GATE MN topic:surface-environment PYQs

How to practice topic:surface-environment

Question 53

Question 54

Question 57

Question 62

Question 64

Question 29

Question 30

Question 47

Question 17

Question 55