Atmospheric Structure, Radiation and Thermodynamics - Atmospheric Science - Engineering Sciences Previous Year Questions

1

2015 · Engineering Sciences · Atmospheric Science · Atmospheric Structure, Radiation and Thermodynamics

Engineering Sciences (XE) 2015

What is the percent relative humidity at which both the dry bulb and wet bulb thermometers would record equal temperatures?

A

0

B

10

C

50

D

100

Open complete paper

2

2017 · Engineering Sciences · Atmospheric Science · Atmospheric Structure, Radiation and Thermodynamics

Engineering Sciences (XE) 2017

The largest contributor to the atmospheric greenhouse effect is

A

CO₂

B

N₂

C

CH₄

D

H₂O

Open complete paper

3

2017 · Engineering Sciences · Atmospheric Science · Atmospheric Structure, Radiation and Thermodynamics

Engineering Sciences (XE) 2017

Planets in the solar system are in radiative equilibrium. Let \( S_0 \), \( \alpha \), \( T_0 \) and \( R \) denote solar constant, albedo, average temperature and radius of a planet, respectively, and \( \sigma \) is Stefan's constant. Then the energy balance of this planet is given by the expression

A

\((1 - \alpha) S_0 = 4 \sigma T_0^4 \)

B

\((1 - \alpha) S_0 = 2 \sigma T_0^4 \)

C

\(\alpha S_0 = \sigma T_0^4 \)

D

\(\pi R^2 (1 - \alpha) S_0 = 4 \sigma T_0^4 \)

Open complete paper

4

2017 · Engineering Sciences · Atmospheric Science · Atmospheric Structure, Radiation and Thermodynamics

Engineering Sciences (XE) 2017

Average surface temperatures of the Sun and the Earth are 6300 K and 285 K, respectively. The ratio of the wavelength of peak radiation of the Earth to that of the Sun is ______.

Check answer

Open complete paper

5

2017 · Engineering Sciences · Atmospheric Science · Atmospheric Structure, Radiation and Thermodynamics

Engineering Sciences (XE) 2017

The thickness of an atmospheric layer between 600 hPa and 500 hPa is 1.5 km. If the layer is isothermal, then its temperature is __________ K.
[Gas constant of air: 287 J kg^-1 K^-1, g: 10 m s^-2]

Check answer

Open complete paper

6

2018 · Engineering Sciences · Atmospheric Science · Atmospheric Structure, Radiation and Thermodynamics

Engineering Sciences (XE) 2018

The most abundant gas in the atmosphere among inert gases is

A

Helium

B

Argon

C

Neon

D

Krypton

Open complete paper

7

2018 · Engineering Sciences · Atmospheric Science · Atmospheric Structure, Radiation and Thermodynamics

Engineering Sciences (XE) 2018

The pair of variables that always exhibit monotonic decrease with height in the atmosphere is

A

Pressure, Temperature

B

Pressure, Ozone concentration

C

Air Density, Pressure

D

Temperature, Water Vapour

Open complete paper

8

2018 · Engineering Sciences · Atmospheric Science · Atmospheric Structure, Radiation and Thermodynamics

Engineering Sciences (XE) 2018

On the summer solstice day, the maximum incident shortwave radiation at the top of the atmosphere over the equator (up to one decimal place) is __________ W m^-2. (Take solar constant as 1368 W m^-2).

Check answer

Open complete paper

9

2018 · Engineering Sciences · Atmospheric Science · Atmospheric Structure, Radiation and Thermodynamics

Engineering Sciences (XE) 2018

In an isothermal atmosphere having a temperature of 15°C, the height at which pressure decreases to 1/10 of its value at the surface is __________ km. (Give the answer to two decimal places.) Take g = 9.8 m s^-2, gas constant R = 287 J kg^-1 K^-1

Check answer

Open complete paper

10

2018 · Engineering Sciences · Atmospheric Science · Atmospheric Structure, Radiation and Thermodynamics

Engineering Sciences (XE) 2018

A numerical model of the atmosphere uses sigma (σ) coordinate system in vertical. At locations P and Q, surface pressures are 1005 hPa and 500 hPa, respectively. Absolute difference in the heights of σ = 0.9 level between these locations is _________ meters. (Give the answer to one decimal place.) Layer mean temperatures at P and Q are 300 K and 270 K, respectively. (Take g = 9.8 m s^-2, gas constant R = 287 J kg^-1 K^-1.)

Check answer

Open complete paper

11

2019 · Engineering Sciences · Atmospheric Science · Atmospheric Structure, Radiation and Thermodynamics

Engineering Sciences (XE) 2019

Ideal gas equation for dry air is expressed as \( p = \rho R_d T \), where \( p \) is pressure, \( \rho \) is density, \( T \) is temperature and \( R_d \) is gas constant. If CO₂ concentration in Earth’s atmosphere quadruples due to fossil fuel burning, then the new gas constant is __________ J kg⁻¹ K⁻¹. (Round off to two decimal places.)
Take the universal gas constant (\( R^* \)) = 8.314 J K⁻¹ mole⁻¹, molecular weight of CO₂ = 44, and present value of \( R_d \) = 287 J kg⁻¹ K⁻¹, present concentration of CO₂ = 500 mg kg⁻¹.

Check answer

Open complete paper

12

2020 · Engineering Sciences · Atmospheric Science · Atmospheric Structure, Radiation and Thermodynamics

Engineering Sciences (XE) 2020

Consider the two atmospheric virtual temperature profiles observed in Delhi given in Figures (i) and (ii) below.

At what times of the day are you most likely to see such profiles?
(i) Midnight and (ii) noon
(i) 3 pm and (ii) 3 am
(i) Sunrise and (ii) sunset
(i) 3 am and (ii) 3 pm

A

(i) Midnight and (ii) noon

B

(i) 3 pm and (ii) 3 am

C

(i) Sunrise and (ii) sunset

D

(i) 3 am and (ii) 3 pm

Open complete paper

13

2020 · Engineering Sciences · Atmospheric Science · Atmospheric Structure, Radiation and Thermodynamics

Engineering Sciences (XE) 2020

The emissivity of polluted air that reflects and transmits 20% and 60% of the incoming solar radiation, respectively, at a given wavelength (correct up to 1 decimal place) is ________.

Check answer

Open complete paper

14

2020 · Engineering Sciences · Atmospheric Science · Atmospheric Structure, Radiation and Thermodynamics

Engineering Sciences (XE) 2020

Assume that pressure varies exponentially with height: \( p(z) = p_0 e^{-z/H} \), where \( p(z) \) is the pressure at a height \( z \) above the surface, \( p_0 \) is the surface pressure, and the scale height \( H = 7.5 \) km. Under these conditions, one-fourth of the total mass of the atmosphere lies above a height (rounded off to 1 decimal place) of ________ km above the surface.

Check answer

Open complete paper

15

2020 · Engineering Sciences · Atmospheric Science · Atmospheric Structure, Radiation and Thermodynamics

Engineering Sciences (XE) 2020

Consider an atmospheric column of depth 300 m at the Earth's surface with an average temperature of 300 K. If the temperature of the layer rises by \( \Delta T = 10 \) °C, the layer depth \( h \) will increase by \( \Delta h \). Assuming \( \Delta T/T = \Delta h/h \), air density remains unchanged at 1 kgm\(^{-3}\) and \( g = 10 \; \text{ms}^{-2} \), the change in surface pressure is ________ kgm\(^{-1}\)s\(^{-2}\).

Check answer

Open complete paper

16

2021 · Engineering Sciences · Atmospheric Science · Atmospheric Structure, Radiation and Thermodynamics

Engineering Sciences (XE) 2021

The water vapour mixing ratio of an air parcel increases from 10 g kg^-1 to 20 g kg^-1 at a constant pressure of 1010 hPa and temperature of 300 K. The change in virtual temperature is ______ K (to one decimal place).

Check answer

Open complete paper

17

2021 · Engineering Sciences · Atmospheric Science · Atmospheric Structure, Radiation and Thermodynamics

Engineering Sciences (XE) 2021

In an atmosphere, temperature (T) decreases linearly with height above the ground (z), i.e., T(z) = T₀ - γ z, where γ is a constant. Surface pressure is 900 hPa. If the atmosphere is at rest, then the value of z at which the pressure decreases to half of that at the surface is $\_\_\_\_$ m (round off to the nearest integer).
Take acceleration due to gravity g = 10 m s⁻², gas constant R = 300 J kg⁻¹ K⁻¹, T₀ = 300 K and γ = 1/30 K m⁻¹, and the atmosphere behaves as an ideal gas.

Check answer

Open complete paper

18

2021 · Engineering Sciences · Atmospheric Science · Atmospheric Structure, Radiation and Thermodynamics

Engineering Sciences (XE) 2021

Suppose, because of the doubling of atmospheric CO₂ concentration, an ocean water column receives an additional net energy input of 4 Wm⁻². If the entire water column of depth 1 km heats up uniformly, the water temperature will increase by 1 K in $\_\_\_\_$ years (round off to the nearest integer).
Assume all the additional heat added is retained and not lost. Take density of seawater = 1000 kg m⁻³; specific heat capacity of seawater = 4200 J kg⁻¹ K⁻¹.

Check answer

Open complete paper

19

2021 · Engineering Sciences · Atmospheric Science · Atmospheric Structure, Radiation and Thermodynamics

Engineering Sciences (XE) 2021

A spherical asteroid, revolving around the sun in a circular orbit, is in radiative balance. Suddenly, the asteroid enters the shadow of a planet and solar radiation is cut off. Assuming that the asteroid emits as a blackbody in the longwave regime, the time taken to reduce the average temperature of the asteroid by 0.5 K is ______ seconds (round off to the nearest integer). Ignore the temporal change in radiation emitted by the asteroid during this cooling period.
The physical properties of the asteroid are: diameter = 2 m, density = 3000 kg m^-3, specific heat = 2000 J kg^-1 K^-1 and albedo = 0.8 in shortwave radiation. Take the solar constant = 500 W m^-2, Stefan-Boltzmann constant = 5.67 x 10^-8 W m^-2 K^-4.

Check answer

Open complete paper

20

2022 · Engineering Sciences · Atmospheric Science · Atmospheric Structure, Radiation and Thermodynamics

Engineering Sciences (XE) 2022

The figure shows a schematic of vertical profiles of concentrations of two gases P and Q in the atmosphere near a coastal station. The correct pair representing P and Q, respectively, is

A

water vapor and CO₂

B

O₃ and water vapor

C

CO₂ and O₃

D

N₂ and O₂

Open complete paper