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# UPSC Geography Climate Question Bank

### done Climatology

• A) Oxygen, carbon dioxide, nitrogen, hydrogen

B) Carbon dioxide, oxygen, nitrogen, hydrogen

C) Hydrogen, nitrogen, carbon dioxide, oxygen

D) Nitrogen, oxygen, carbon dioxide, hydrogen

•  I. Its maximum concentration is 20 to 25 km above the earth's surface. II. It saves us from the intense heat of the sun.

A) Statement I is correct

B) Statement II is correct

C) Both Statement I and Statement II are correct

D) Neither I nor II is correct

•  1. Atmosphere is odourless, tasteless and colourless 2. Atmosphere is held to the earth by its gravitational force and is an integral part of the earth. 3. Hydrogen present in the air is a heavy gas and is confined to the lower layers of the atmosphere only. 4. Dust particles present in the atmosphere act as hydroscopic matter.

A) 1 and 2 only

B) 1, 2 and 3 only

C) 2, 3 and 4 only

D) 1, 2 and 4 only

•  1. Most of the weather phenomena are associated with stratosphere. 2. Lower part of stratosphere is called ozonosphere
Which of the above statements is/are correct?

A) 1 only

B) 2 only

C) Both 1 and 2

D) Neither 1 nor 2

•  List I (Atmospheric layer) List II (Special feature) A. Troposphere 1. Mother of pearls B. Stratosphere 2. Normal lapse rate C. Ionosphere 3. Aurora Borealis D. Mesosphere 4. Rise in temperature

A) A-4 B-2C-1D-3

B) A-3B-4C-1D-2

C) A-2B-1C-3D-4

D) A-1B-3C-4D-2

•  1. Gases in hetero sphere are not evenly mixed 2. Troposphere contains over 90% of the earth's water vapour 3. Hydrogen is confined to lower layers of the atmosphere 4. Temperature at troop pause is less at the equator than at the poles

A) 1, 2 and 3 only

B) 1, 2 and 4 only

C) 2, 3 and 4 only

D) 1, 3 and 4 only

•  1. Tropo pause extends to a height of 18 km at the equator and only 10 km at the poles. 2. Ionosphere is useful for radio transmission.
Which of the above statements is/are correct?

A) 1 only

B) 2 only

C) Both 1 and 2

D) Neither 1 nor 2

• A) Troposphere, Stratosphere, Mesosphere, Ionosphere

B) Troposphere, Exosphere, Mesosphere, Stratosphere

C) Stratosphere, Mesosphere, Exosphere, Troposphere

D) Ionosphere, Troposphere, Mesosphere, Stratosphere

•  I. Water vapour in the atmosphere decreases with altitude. II. It increases from equator towards the poles. III. About 90% of atmospheric water vapour lies below 6 km. IV. It preserves earth's radiated heat.

A) I, II, III???

B) I, III, IV

C) I, II, III, IV

D) II, III, IV

•  1. Chemically it is divided into homosphere and heterosphere. 2. Molecular layer extends from 200 to 1100 km. 3. Water vapour present in the air produces the optical phenomena of red and orange hues in the sky at sunrise and sunset which are known as dawn and dusk respectively. 4. Thermosphere is divided into ionosphere and exosphere
Which of the above statements are correct?

A) 2, 3 and 4 only

B) 1, 2 and 3 only

C) 1, 3 and 4 only

D) 1, 2 and 4 only

•  1. Ionosphere deflects long wave, medium wave and short wave radio waves and help in radio transmission. 2. Ionosphere is the layer of convection currents
Which of the above statements is/are correct?

A) 1 only

B) 2 only

C) Both 1 and 2

D) Neither 1 nor 2

•  Assertion (A): The thickness of the atmosphere is the maximum over the equator.????? Reason (R): High insulation and strong convection currents occur over the equator.

A) Both A are R are individually true and R is the correct explanation of A

B) Both A and R are individually true but R is not the correct explanation of A

C) A is true but R is false

D) A is fast false but R is true

•  1. It contains about three-fourth of the total mass of the atmosphere. 2. There is fall in temperature with increasing height. 3. Its height is more at equator than at the poles. All the weather phenomena occur in this layer.
Identify this layer

A) Ionosphere

B) Mesosphere

C) Stratosphere

D) Troposphere

•  I. They act as hydroscopic nuclei around which water vapour condenses to produce cloud. II. They produce dawn and dusk. III. They have no role in the apparent colour of the sky.

A) I and II

B) II and III

C) I, II and III

D) I and III

•  1. The diffused light that occurs before sunrise is known as dawn. 2. Light is scattered by the molecules of atmosphere gases. 3. The duration of dawn and twilight varies with altitude. 4. Lower sun angles produces longer dawn and twilight.
Which of the above statements are correct?

A) 1 and 2 only

B) 2 and 3 only

C) 3 and 4 only

D) 1, 2, 3 and 4

•  List I (Atmospheric layers) List II (Characteristics) A. Troposphere 1. Normal lapse rate B. Stratosphere 2. Mother of pearls C. Ionosphere 3. Reflection of radio waves D. Exosphere 4. Very rare air

A) A-1 B-2C-3D-4

B) A-2B-3C-4D-1

C) A-3B-4C-1D-2

D) A-4 B-3C-2D-1

•  List I (Characteristics) List II (Atmospheric layer) A. Fall in temperature with height 1. Ionosphere B. Reflects radio waves??? 2. Troposphere C. Contains ozone gas???? 3. Exosphere D. Increase in temperature with height 4. Stratosphere

A) A-2 B-1C-4D-3

B) A-1B-3C-2D-4

C) A-4B-3C-1D-2

D) A-3B-4C-2D-1

•  I. Increasing use of the chlorofluorocarbons has resulted in depletion of ozone layer in the atmosphere. II. The largest ozone hole is found on the Arctic Ocean

A) Statements I and II are correct

B) Neither I nor II is correct

C) Only I is correct

D) Only II is correct

•  1. It extends from the earth's surface up to an altitude of 80-90 km. 2. It has heterogeneous chemical composition. 3. Kennedy- Heaviside layer is an important part of ionosphere. 4. This part of the atmosphere is a function of revolutionary process in the atmosphere.

A) Only 1 is correct

B) Only 1 and 2 are correct

C) Only 1, 2 and 3 are correct

D) 1, 2, 3 and 4 are correct.

•  I. Large distance of the earth from the sun. II. Small size of the earth as compared to sun. III. Empty space between the sun and the earth. IV. The gaseous mass surrounding the earth.

A) Statement I, II and III are correct.

B) Statement II, III and IV are correct.

C) Statement I and II are correct.

D) Statement III and IV are correct.

•  1. Heat energy radiated by the sun into space is known as solar insolation. 2. Slope of land does not have any effect on the amount of solar radiation received at a place.
Which of the above statements is/are correct?

A) 1 only

B) 2 only

C) Both 1 and 2

D) Neither 1 nor 2

•  I. There are no clouds and other weather phenomenon. II. Uniform temperature increases engine efficiency. III. The presence of ozone gas increases fuel efficiency IV. Air resistance is at its maximum.
Which statement is/are correct?

A) Only I

B) I and II

C) I, II and III

D) I, II, III and IV

• A) Inclination of sun's rays

B) Presence of clouds in the atmosphere

C) Duration of day

D) Rotation of the earth

• A) Solar radiation absorbed by the earth's surface.

B) Solar radiation absorbed by the atmosphere.

C) Solar radiation reflected back by the earth's surface to the space.

D) Ratio between the total solar radiation falling upon a surface and amount reflected in percentage,

•  1. The reflective quality of a surface, expressed in percentage of the total energy received known as its albedo. 2. The albedo of water surface varies from 2 to 99 per cent depending on the angle of incidence of the sun's rays. 3. Albedo of old snow is layer than that of the fresh snow. 4. The overall albedo of clouds is larger than other surface.
Which of the above statements is/are correct?

A) 1, 2 and 3 only

B) 2, 3 and 4 only

C) 1, 2 and 4 only

D) 1, 2, 3 and 4

•  1. Taiga 2. Tropical evergreen 3. Tropical deciduous 4. Tundra
The correct sequence in decreasing order of the Albedo values of those ecosystems is;

A) 1, 4, 3, 2

B) 4, 1, 3, 2

C) 4, 1, 2, 3

D) 1, 4, 2, 3

•  I. Balance of heat received and emitted by the earth is called its heat budget. II. Less than half of the solar insulation received at the top of the atmosphere reaches the earth's surface.

A) I is correct

B) II is correct

C) Both I and II are correct

D) Neither I nor II is correct

•  I. Insulation is the heat energy and temperature is the measure of heat intensity. II. Insulation is measured in calories whereas temperature is expressed in degrees ($^{o}C$or$^{o}F$). III. Insolation is the effect and temperature is the cause.
Find out the correct statements using the following code.

A) I only

B) I and II only

C) I, II and III

D) II and III only

•  List I?? ???????? (Process)??????? List II (Definition) A. Absorption?? 1. The reflection quality of a surface B. Albedo????? 2. Solar radiation which is intercepted by the earth. C. Refraction?? 3. The bending effect that occurs when insolation enters the atmosphere D. Insolation? ?4. Assimilation and conversion of radiation from one form to another in a medium

A) A-4 B-1C-3D-2

B) A-2B-3C-1D-4

C) A-1B-4C-2D-3

D) A-3B-2C-4D-1

•  1. Skin cancer particularly to white skinned people. 2. Crop damage 3. Throat irritation and fatigue 4. Injury to some aquatic life
Find out the correct answer using code given below.

A) 1 and 2 only

B) 1, 2 and 3 only

C) 1, 2, 3 and 4

D) 2, 3, 4 only

•  A. Torrid zone 1. Between Tropic of Cancer and Tropic of Capricorn B. North Temperate Zone 2. Between Tropic of Capricorn and Antarctic Circle C. South Temperate Zone 3. Between Tropic of Cancer and Arctic Circle D. North Frigid Zone??? 4. Between Arctic Circle and North Pole

A) A-1 B-2C-3D-4

B) A-4B-3C-1D-2

C) A-1B-3C-2D-4

D) A-3B-2C-4D-1

• A) Large absorption of solar radiation by pure air.

B) Lack of vertical movement of air.

C) Presence of ozone gas.

D) Presence of minute particles.

•  List I List II A. Temperature falls 1. Ionosphere with height B. Reflects radio waves back 2. Stratosphere C. Contains most of Ozone 3. Troposphere D. Fall in temperature stops 4. Tropopause

A) A-2 B-3C-4D-1

B) A-1B-2C-3D-4

C) A-4B-3C-2D-1

D) A-3B-1C-2D-4

• A) Tropical rainforests

B) Tropical hot deserts

C) Sub polar areas

D) Highlands of Central Asia

•  List I (Atmospheric Layers) List II (Characteristics) A. Troposphere??? 1. All weather phenomena B. Stratosphere??? 2. Presence of ozone layer C. Ionosphere????? 3. Electricity charged particles D. Mesosphere???? 4. Aurora Borealis

A) A and B

B) A, B and C

C) B, C and D

D) A, B, C and D

• A) Short waves and long waves

B) Short waves and short waves

C) Long waves and long waves

D) Long waves and short waves

•  1. Nights are short 2. Sky is covered with clouds 3. Weather is stable 4. Air is dry
Which of the above factors are correct?

A) 1 and 2 only

B) 2 and 3 only

C) 3 and 4 only????

D) 1 and 4 only

•  List I????????????????? (Phenomena)?????????? List II (Type of temperature inversion) I. Air moving from high area to low area along the valley floor 1. Air drainage inversion II. Intense cooling of earth's surface due to rapid radiation 2. Surface inversion III. Warm airs blows over cold air??? ? 3. Advectional inversion IV. Cold air mass pushes up the warm air mass 4. Frontal inversion

A) I and II??

B) I, II and III

C) I, II, III and IV??

D) II and IV

•  1. Regular fall of temperature with height in the troposphere is known as normal lapse rate. 2. Rise in temperature with height is called inversion of temperature.????????????????
Which of the above statements is/are correct??

A) 1 only

B) 2 only????????????

C) both 1 and 2????

D) Neither 1 nor 2??

• A) Equatorial region

B) Hot desert region

C) Monsoon region

D) Mediterranean region

• A) Savanna region

B) Equatorial region

C) Taiga region

D) Monsoon region

•  1. In the troposphere the temperature falls at the rate of ${{10}^{o}}C$ per km altitude. 2. Cloudy days and nights are cooler than dry days and nights
Which of the above statements is/are correct??

A) 1 only

B) 2 only

C) Neither 1 nor 2

D) Both 1 and 2

•  1. Days and nights are longest in June and December respectively in the northern hemisphere. 2. Tropic of Cancer and Tropic of Capricorn represent the farthest northern and southern limits of the sun's vertical rays respectively. 3. At the time of summer Solstice, Norway and Finland never get sunshine. 4. At the time of winter solstice, the Antarctic continent is in complete darkness.
Which of the above statements are correct?

A) 1 and 2 only

B) 2 and 3 only

C) 3 and 4 only

D) 1, 2, 3 and 4

•  [a] Moscow in the Russian Federation has the highest annual range of temperature in the world. [b] Singapore has one of the lowest annual ranges of temperature in the world.

A) 1 only

B) 2 only

C) Both 1 and 2

D) Neither 1 nor 2

•  1. Interior parts of the continents experience higher annual range of temperature as compared to the coastal areas. 2. Thermal equator remains at the equator throughout the year. 3. Northern hemisphere experiences higher annual range of temperature than southern hemisphere. 4. Some parts of equatorial Africa experience higher diurnal range of temperature than the annual range of temperature.

A) 1, 2 and 3 only

B) 2, 3 and 4 only

C) 1, 3 and 4 only

D) 1, 2 and 4 only

•  1. Isotherms almost run parallel to the latitudes. 2. In the northern hemisphere, the isotherms bend equator ward while crossing landmasses and pole ward while crossing the oceans.
Which of the above statements is/are correct?

A) 1 only

B) 2 only

C) Both 1 and 2

D) Neither 1 nor 2

•  1. Altitude above sea level 2. Moisture in the air 3. Rotation of the earth 4. Climatology 1.73

A) 1 and 2

B) 1, 2 and 3

C) 1, 2, 3 and 4

D) 2, 3 and 4

• A) Equatorial low, Sub-Polar low, Polar High, Sub-Tropical High

B) Sub-Tropical High, Polar High, Sub-Polar low, Equatorial low

C) Sub-Polar low, Polar High, Sub-Tropical High, Equatorial low

D) Equatorial low, Sub-Tropical High, Sub- Polar, Polar High

•  I. They have to travel through smaller thickness of the atmosphere. II. They have to heat lesser area on the earth's surface.

A) Only 1 is correct

B) Only II is correct

C) Both I and II are correct

D) Neither I nor II is correct.

•  List I List II A. Doldrums?????? 1. Equatorial B. Horse Latitudes 2. Polar High C. Frigid Zone???? 3. Sub-tropical high D. Torrid Zone???? 4. Tropics within Tropic of Cancer and Tropic of Capricorn

A) A - 1, B - 2, C - 3, D - 4

B) A - 1, B - 3, C - 2, D - 4

C) A - 2, B - 3, C - 1, D - 4

D) A - 3, B - 1, C - 1, D - 2

• A) There is extremely low atmospheric pressure

B) It is an area of strong horizontal winds

C) There is no horizontal wind and only vertical currents are found

D) Humidity in the air is very high

•  1. High temperature 2. High water vapour content in the air 3. Maximum centrifugal force on the equator 4. Convergence of air from the subtropical high pressure belts

A) 1, 2 and 3 only

B) 2, 3 and 4 only

C) 1, 3 and 4 only

D) 1, 2, 3 and 4

•  1. There is very little flow of air 2. The air continuously descends 3. The Inter-tropical convergence Zone (ITZ) formed by the converging winds maintains its position at the equator throughout the year. 4. The converging air is dry.

A) 1 and 4 only

B) 2 and 3 only

C) 1 and 2 only

D) 3 and 4 only

• A) Frictional force??

B) Geostrophic force

C) Deflection force

D) Centripetal force

•  List I (Pressure cells) List II (Avg Temperature/ moisture) A. Equatorial low pressure trough 1. Cold/dry B. Sub-Tropical high pressure cells 2. Cool/wet C. Sub-polar low pressure cells 3. Warm/dry D. Polar high pressure cells 4. Hot/wet

A) A-1, B-2, C-3, D-4

B) A-2, B-3, C-1, D-4

C) A-4, B-3, C-2, D-1

D) A-3, B-4, C-1, D-2

•  1. They are also called Ross by waves. 2. They are usually found near tropo pause. 3. They travel from west to east in the northern hemisphere and from east to west in the southern hemisphere 4. They travel at very high velocity 5. They are usually sinuous in character
Which of the above statements are correct?

A) 1, 2, 3 and 4 only

B) 1, 2, 3 and 5 only

C) 1, 2 and 4 only

D) 1, 2, 4 and 5 only

• A) Jet streams are strong winds with normal speed of 100 to 300 km/hr

B) Discovery of the Jet Streams was made by American airplanes during the World War I

C) Jet streams shift pole wards during summer and equator wards during winter season.

D) Velocity of the Jet stream in winter is almost twice the velocity the summer.

•  1. Doldrum?????????? Equatorial low pressure belt 2. Horse Latitudes? Sub-polar low pressure belt 3.? Torrid zone???? Sub-tropical high pressure belt

A) 1 only

B) 1 and 2 only

C) 2 and 3 only

D) 1, 2 and 3

• A) Atmospheric pressure

B) Atmospheric moisture

D) Insolation

• A) Low temperature

B) Divergence of air

C) Convergence of air

D) Descending of air

• A) Pressure distribution

C) Revolution of the earth

D) Rotation of the earth

• A) Sub-tropical high and equatorial low

B) Equatorial low and sub-tropical high

C) Sub-tropical high and sub-polar low

D) Sub-polar low and sub-tropical high

•  1. They constantly blow from tropical high pressure belt to equatorial low pressure belt. 2. They derive their name from the trade which was carried on with help of these winds in the medieval period. 3. They bring lot of rainfall to the equatorial low pressure belt. 4. They are deflected from their path due to the earth's rotation.

A) 1 and 2 only

B) 2 and 3 only

C) 2 and 4 only

D) 1 and 4 only

•  I. It is a low pressure area near the equator. II. It is at the convergence of NE and SE trade winds. III. It shifts its position to the north of equator in the summer and to the south of equator in the winter season.

A) I is true

B) II, III are true

C) I, II, III are true

D) I, III are true

• A) Pressure belts

B) Velocity of wind

C) Direction of winds

D) Deflection of winds

• A) They blow from sub-tropical high pressure belts to sub-polar low pressure belts.

B) They cause heavy rainfall on the eastern margins of the continents.

C) They are deflected due to the earth's rotation.

D) They are best developed between ${{40}^{o}}$ and ${{65}^{o}}$ south latitudes.

•  1. Effectiveness of Coriolis force decreases from equator towards the poles 2. Moist air is heavier than dry air.
Which of the above statements is/are correct?

A) 1 only

B) 2 only

C) Both 1 and 2

D) Neither 1 nor 2

• A) Equatorial low pressure

B) Sub-tropical high pressure

C) Sub-polar low pressure

D) Polar high pressure

• A) Trade winds

B) Western winds

C) Monsoon winds

D) Polar winds

• A) Monsoon winds

B) Land and Sea Breezes

C) Mountain and valley Breezes

• A) Continents of the Northern Hemisphere

B) Oceans of the Northern Hemisphere

C) Continents of the Southern Hemisphere

D) Oceans of the Southern Hemisphere

•  1. They blow uninterrupted in the Northern and Southern Hemisphere. 2. They blow with great strength and constancy. 3. Their direction is generally from north- west to south-east in the southern hemisphere 4. Overcast skies, rain and raw weather are generally associated with them.
Which of the above statements are correct?

A) 1, 2 and 3 only

B) 2, 3 and 4 only

C) 1, 3 and 4 only

D) 1, 2 and 4 only

•  1. Southern hemisphere has less landmass as compared to northern hemisphere. 2. Coriolis force is higher in southern hemisphere as compared to northern hemisphere.
Which of the statements given above is/are correct?

A) 1 only

B) 2 only

C) Both 1 and 2

D) Neither 1 nor 2

• A) Stormy

B) Cloudy and dry

C) Calm

D) Hot and sunny

• A) Water vapour in stratus clouds

B) Ice crystals in cirrocumulus clouds

C) Ice crystals in cirrus clouds

D) Dust particles in stratus clouds

• A) India and Pakistan

B) Bangladesh and Myanmar

C) Indonesia and Philippines

D) Brazil and Bolivia

•  List I (Theory of monsoon winds) List II (Scholar) 1. Classical Theory??? 1. Edmund Hally 2. Air Mass Theory???? 2. M.T. Yin 3. Jet Stream Theory?? 3. H. Flohn

A) 1 only

B) 1 and 2 only

C) 2 and 3 only

D) 1, 2 and 3

• A) La Nina

B) Movement of Jet Stream

C) El Nino and Southern oscillations

D) Greenhouse effect on global level

• A) There is complete reversal of direction of wind flow according to season.

B) Affects most parts of south-east Asia

C) Rainfall is seasonal

D) Not affected by El-Nino

•  1. La Nina is characterized by unusually cold ocean temperature in equatorial Indian Ocean whereas El Nino is characterized by unusually warm ocean temperature in the equatorial Pacific Ocean. 2. El Nino has adverse effect on monsoon climate
Which of the statements given above is/are correct?

A) 1 only

B) 2 only

C) Both 1 and 2

D) Neither 1 nor 2

•  1. Normal El Nino forms in the Central Pacific Ocean whereas El Nino Modoki forms in Eastern Pacific ocean. 2. Normal El Nino results in diminished hurricanes in the Atlantic Ocean but El Nino Modoki results in a greater number of hurricanes with greater frequency.
Correct statements:

A) 1 only

B) 2 only

C) both 1 and 2

D) Neither 1 nor 2

•  Assertion (A): Wind patterns are clockwise in the northern hemisphere and anti-clockwise in the southern hemisphere. Reason (R): The directions of wind pattern in the northern and the southern hemisphere are governed by the Coriolis Effect.

A) Both A and R are true and R is the correct explanation of A

B) Both A and R are correct but R is not a correct explanation of A

C) A is true but R is false

D) A is false but R is true

•  1. They are more pronounced in the tropical zone 2. Sea breezes are more effective at night time 3. The effect of land and sea breezes decreases with latitude 4. Land breeze has smaller seaward penetration than the landward penetration of sea breeze.

A) 1, 2 and 3

B) 2, 3 and 4

C) 1, 2 and 4

D) 1, 3 and 4

• A) Mediterranean Sea

B) Baltic Sea

C) Bering Sea

D) Caribbean Sea

•  1. Speed of the valley breeze is approximately proportional to the square root of the temperature differences between the top and bottom of the valley 2. Mountain breezes generally cause inversion of temperature in the valley
Which of the above statements is/are correct?

A) 1 only

B) 2 only

C) Both 1 and 2

D) Neither 1 nor 2

• A) Edmond Halley attributed the origin of monsoon winds to differential heating of land and sea.

B) Flohn considered monsoon as a modification of planetary winds of the tropics.

C) El Nino adversely affects the monsoon winds.

D) La Nina has no effect on the monsoon winds.

• A) Trade winds and monsoon winds.

B) Monsoon winds and land and sea breezes.

C) Land and sea breezes and mountain and valley breezes.

D) Mountain and valley breezes and trade winds.

•  I. India II. China III. Japan IV. Bangladesh

A) Only I

B) I and II only

C) I, II, III only

D) I, II, III, IV

• A)

 Local wind???????? Area ?Bora?????????? ?????? Adriatic coast

B)

 Local wind???????? Area Mistral?????????????? Southern France

C)

 Local wind???????? Area ?Berg????????????????? Spain

D)

 Local wind???????? Area ?Khamsin?????????? Egypt

• A) Harmattan??????

B) Sirocco

C) Khamsin

D) Brickfielder

•  I. They blow down the eastern slopes of Rockies in U.S.A. and Canada after crossing these mountain ranges. II. They are known as snow eaters in the Great Plain of North America. III. They cause heavy destruction to crops and grasslands in the areas affected by them.

A) Only I is true

B) I and II are true

C) I, II, III are true

D) II and III are true

•  List I List II A. Foehn??????? 1. Leeward side of the Alps B. Chinook???? 2. Rockies of North America C. Mistral?????? 3. Rhone Valley D. Brickfielder? 4. Australia

A) A-2, B-1, C-4, D-3

B) A-1, B-2, C-3, D-4

C) A-3, B-4, C-1, D-2

D) A-4, B-2, C-3, D-1

•  List I (Local wind) List II (Country/Region) A. Getii??????????? 1. Tarim Basin B. Kharaburan????? 2. Libya C. Harmettan?????? 3.? Adriatic sea D. Bora??????????? 4.? Sahara

A) A-2, B-1, C-4, D-3

B) A-1, B-2, C-3, D-4

C) A-3, B-4, C-1, D-2

D) A-4, B-2, C-3, D-1

•  List I (Wind) List II (Characteristics) A. Chinook??? 1. Snow eater B. Khamsin??? 2. Wind of fifty days C. Sirocco????? 3.? Cause 'blood rain' in Italy D. Harmattan?? 4. Known as doctor in? Guinea

A) A-1, B-2, C-3, D-4

B) A-4, B-3, C-2, D-1

C) A-3, B-2, C-4, D-1

D) A-2, B-4, C-1, D-3

• A) Australia and New Zealand

B) India and New Zealand

C) Brazil and Argentina

D) China and Japan

• A) Bora

B) Blizzard

C) Brickfield

D) Mistral

• A)

 Local wind Area ?Bora Adriatic coast

B)

 Local wind Area ?Mistral?????????????? Southern France

C)

 Local wind???????? Area ?Nevados?????????? Spain

D)

 Local wind???????? Area ?Khamsin??????? Egypt

• A)

 Local wind??? Area ?Maestro?????????? Central Mediterranean region

B)

 Local wind Area ?Pampero Argentina and Uruguay

C)

 Local wind Area ?Leveche??????? Spain

D)

 Local wind??? Area ?Haboob??????? Saudi Arabia

•  List I?????????????? List II (Local wind)??????? (Region) A. Fohn??????????? 1. Argentina B. Sarmun???????? 2. Kurdistan C. Santa Ana?????? 3. California D. Zonda????????? 4. Alps

A) A-2, B-4, C-1, D-3

B) A-4, B-2, C-3, D-1

C) A-2, B-4, C-3, D-1

D) A-4, B-2, C-1, D-3

•  1. Wind speed is influenced by the topographical features. 2. The effect of surface friction extends to a height of about 500m (1650 ft) 3. Rougher surfaces produce more friction. 4. Wind speed changes according to pressure gradient.
Which of the above statements is/are correct?

A) 1 and 2only

B) 1, 2 and 3 only

C) 1, 2, 3 and 4

D) 2, 3 and 4 only

• A) Chinook is a blessing to Great Plain of North America as it raises temperature swiftly and considerably.

B) Fohn blows over Alps of Poland.

C) Nevodos blows from Andean snow fields to high valleys of Ecuador.

D) Shamal is a dry dust laden wind blowing across the plains of Iraq in Tigris-Euphrates basin.

• A) Evaporation depends upon temperature and dryness of the air.

B) Clouds favour evaporation and increase the amount of evaporation.

C) Maximum water vapour in the air is found over the equator.

D) Evaporation taking place from vegetation is known as transpiration. Which of the above statements as wrong?

• A) Absolute Humidity

B) Specific Humidity

C) Relative Humidity

D) Optimum Humidity

• A) Amount of water vapour actually present in the air at a particular temperature to the amount of water vapour required to saturate the same air at the same temperature. Climatology 1.79

B) Amount of water vapour actually present in the air to the maximum water vapour which can be held in the same water at the same temperature.

C) Weight of moist air to that of dry air.

D) Volume of moisture to weight of moist air at the same temperature.

•  1. Increasing the moisture without increasing the temperature. 2. Increasing the temperature without increasing the moisture. 3. Decreasing the temperature without increasing the moisture. 4. Decreasing the moisture without decreasing the temperature.

A) 1 and 2

B) 1 and 3

C) 2 and 3

D) 3 and 4

•  1. Absolute humidity is expressed in terms of grams of moisture per kilogram of air. 2. Specific humidity is expressed as grams of moisture per cubic metric of air. 3. Relative humidity has no unit and is expressed in terms of percentages.

A) Only 1 is correct

B) Only 2 is correct

C) Only 3 is correct

D) 1, 2 and 3 are correct

•  1. Absolute humidity is the total weight of moisture contained per volume of air at a defined temperature. 2. Specific humidity is the mass of water vapour in grams contained in one kg of air. 3. Relative humidity is the ratio of water vapour actually present in the air having definite volume and temperature to the maximum amount the air can hold. 4. Humidity capacity is the moisture content of air measure in gm/cc.

A) 1 and 2 only

B) 2 and 3 only

C) 1, 2 and 3 only

D) 1, 2, 3 and 4

• A) Condensation starts

B) Dew starts evaporating

C) Water starts freezing

D) Water vapours in the air are frozen

• A) Temperature of the air falls below dew point.

B) Temperature of the air falls below freezing point.

C) Additional moisture is added to air.

D) Volume of air is increased without any addition of heat. Which of the above statements is wrong?

• A) Long nights

B) Calm air

C) Overcast sky

D) High relative humidity

•  1. Clear sky 2. Calm air 3. Low relative humidity 4. Temperature below freezing point

A) 1, 2 and 3

B) 1, 2 and 4

C) 2, 3 and 4

D) 1, 3 and 4

• A) Fog is a sort of cloud with its base near or at the ground.

B) Fog is generally formed during winter nights.

C) It disappears after sun rise.

D) Fog contains more moisture than mist. Which of the above statements is wrong?

•  I. Smog is a mixture of fog and smoke. II. It appears over urban and industrial areas.

A) I is correct

B) I is correct

C) I and II are correct

D) Neither I nor II is correct

• A) Stratus

B) Altostratus

C) Cirrus

D) Altocumulus

• A) Cumulus

B) Cumulonimbus

C) Cirrus

D) Altocumulus

•  List I (Clouds) List II (Possible weather changes) A. Altostratus????? 1. Impending rain or snow B. Cumulus?????? 2. Fair weather C. Stratocumulus?? 3. Possibility of rain D. Cirrus????????? 4. Showery weather

A) A-1, B-2, C-3, D-4

B) A-1, B-4, C-3, D-2

C) A-2, B-3, C-4, D-1

D) A-3, B-1, C-2, D-4

• A) Conversion of water vapour into rain.

B) Conversion of water vapour into rain and snow.

C) Conversion of water vapour into rain, snow and fog.

D) Fall of water vapour on the ground in any form of liquid and solid.

• A) Unsaturated air, condensation, dew point, precipitation

B) Condensation, dew point, saturated air, precipitation

C) Unsaturated air, condensation, saturated air, dew point, precipitation

D) Unsaturated air, dew point, condensation, precipitation

•  1. Air is saturated when the relative humidity is 100 percent 2. Air is saturated when dew point is reached 3. Air is saturated when freezing point is reached
Which of the above statements is/are correct?

A) 1 and 2 only

B) 2 and 3 only

C) 1 and 3 only

D) 1, 2 and 3

•  1. Heating or cooling of descending or ascending air respectively without any change in heat content. 2. Rise in temperature of the air after injecting heat in the air. 3. Fall in temperature of the air after heat is taken out of air.
Which of the above statements is/are correct?

A) 1 only

B) 1 and 2 only

C) 2 and 3 only

D) 1, 2 and 3

• A) It occurs daily in the afternoon in the equatorial region

B) It is of a short duration and stops before sunset

C) It occurs in the form of heavy showers

D) It makes cirrostratus clouds.

• A) It requires a mountain barrier across the wind direction.

B) Areas near the mountain slope receive the maximum rainfall.

C) Windward slope gets maximum rainfall while leeward slope gets minimum rainfall.

D) The windward slope is characterized by stratus clouds whereas leeward slopes are characterized by cumulus clouds.

•  List I List II 1. Vertical circulation of air Orographic rainfall 2. Mountain range coming in the way of moisture laden winds Conventional rainfall 3. Warm moist air mass riding over cold dry air mass Cyclonic rainfall

A) 1

B) 1 and 2

C) 2

D) 3

•  List I (Type of Rainfall) List II (Area) A. Convectional rainfall 1. Western Europe B. Orographic rainfall ?? 2. Western Ghats C. Cyclonic rainfall of Western Ghats 3. Areas to the east D. Rainshadow??????? 4. Equatorial region

A) A-1, B-2, C-3, D-4

B) A-4, B-2, C-1, D-3

C) A-2, B-3, C-1, D-4

D) A-4 ,B-3, C-2, D-1

• A) Prevent cold waves from the sky from descending on earth.

B) Reflect back the heat given off by earth

C) Produce heat and radiate it towards earth

D) Absorb heat from the atmosphere and send it towards earth.

•  Assertion (A): Areas near the equator receive rainfall throughout the year Reason (R): High temperature and high humidity cause convectional rain in most afternoons near the equator.
In the context of the above statements, which one of the following is correct?

A) Both A and R is true and R is the correct explanation of A

B) Both A and R is true but R is not the correct explanation of A

C) A is true but R is false

D) A is false but R is true

•  1. In the middle latitudes, east coast regions receive more rainfall than their western counterparts. 2. Windward slopes of the hills receive abundant rainfall but leeward slopes are almost dry. 3. In the tropics, west coasts are wetter than east coasts. 4. Precipitation is abundant in middle latitudes.
Which of the above statements is/are correct?

A) 1 only

B) 2 only

C) 1 and 2 only

D) 3 and 4 only

•  1. Condensation 2. High temperature and humidity 3. Orography 4. Vertical wind
Thunder cloud development is due to which of these phenomena?

A) 1 and 2

B) 2, 3 and 4

C) 1, 3 and 4

D) 1, 2, 3 and 4

•  1. Meeting of cumulonimbus clouds in the sky 2. Lightning that separates the nimbus clouds 3. Violent upward movement of air and water particles
Select the correct answer using the codes given below

A) 1 only

B) 2 and 3

C) 1 and 3

D) None of the above produces the thunder

•  1. Equatorial region???? Rainfall throughout the year 2. Monsoon region????? Rainfall mainly in summer season 3. Mediterranean region? Rainfall mainly in winter season
Which of the above pairs is/are correctly matched?

A) 1 only

B) 2 only

C) 1 and 2 only

D) 1, 2 and 3

• A) Massive and thick

B) Has homogeneous temperature and humidity

C) Has specific source regions

D) Moves rapidly from the source region Which of the above statements is not correct?

•  (1) Stable air mass (2) Unstable air mass (3) Warm air mass (4) Cool air mass

A) 2 and 3

B) 1 and 2

C) 1 and 4

D) 3 and 4

•  List I (Air mass) List II (Property) A. Maritime Polar?????? 1. Cool dry B. Continent Polar????? 2. Cool moist C. Maritime Tropical??? 3. Warm moist D. Continental Tropical 4. Warm dry

A) A-4, B-3, C-1, D-2

B) A-2, B-1, C-3, D-4

C) A-3, B-4, C-2, D-1

D) A-1, B-2, C-4, D-3

•  1. Sloping boundary surface between contrasting air masses is called a front. 2. A warm front pushes the cold front above and the cold front loses contact with the ground.
Which of the above statements is/are correct?

A) 1 only

B) 2 only

C) Both 1 and 2

D) Neither 1 nor 2

•  1. A given air mass has homogeneity of temperature and humidity. 2. Air masses originate from particular regions known as source regions. 3. Air masses are influenced by the weather of area visited by them.
Which of the above statements is/are correct?

A) 1 and 2 only

B) 2 and 3 only

C) 1 and 3 only

D) 1, 2 and 3

•  1. They originate from well-defined source regions and acquire their basic properties from these regions. 2. The properties of air masses remain the same even if they move from one region to another region.
Which of the above statements is/are correct?

A) 1 only

B) 2 only

C) Both 1 and 2

D) Neither 1 nor 2

•  1. A front is formed when air masses with different characteristics meet each other. 2. A front is a sharp boundary between two air masses. 3. A front formed between polar and tropical air masses is known as polar front.

A) 1 and 2

B) 2 and 3

C) 1 and 3

D) 1, 2 and 3

•  1. Cold front has a sleeper slope than warm front. 2. Weather along a warm front changes more quickly than along cold front.
Which of the above statements is/are correct?

A) 1 only

B) 2 only

C) Both 1 and 2

D) Neither 1 nor 2

• A) Polar Maritime

B) Polar Continental

C) Tropical Maritime

D) Tropical Continental

• A) Low pressure surrounded by high pressure on all sides.

B) High pressure surrounded by low pressure on all sides.

C) Subsidence of air.

D) Divergence of air. Which of the above statements is correct?

•  I. Low pressure II. Convergent air III. Change in wind direction due to Coriolis force IV. Ascending air at the centre

A) I and II

B) I, II and III

C) I, II and IV

D) I, II, III and IV

• A) They originate in temperate lands.

B) Their origin is best explained by the Polar Front Theory of Bjerknes.

C) They are of smaller size than the tropical cyclones.

D) Their arrival is indicated by rise in temperature and fall in atmospheric pressure.

•  1. A temperate cyclone is formed when a cold air mass meets a warm air mass. 2. Before the arrival of the temperate cyclone, the sun looks paler and there is lunar halo. 3. The arrival of a temperate cyclone is indicated by rise in temperature.
Which of the above statements is/are correct?

A) 1 only

B) 2 only

C) 1 and 2 only

D) 1, 2 and 3

• A) North Atlantic Ocean

B) North Pacific Ocean

C) Mediterranean Sea

D) Caribbean Sea

• A) Fogginess and poor visibility

B) Unsettled weather

C) Movement from west to east

D) Torrential rainfall

•  1. In a temperate cyclone, warm air sector is surrounded by cold air sector. 2. A fully grown temperate cyclone is circular in slope.
Which of the above statements is/are correct?

A) 1 only

B) 2 only

C) Both 1 and 2

D) Neither 1 nor 3

•  1. Most of the tropical cyclones are circular in shape. 2. Most of the tropical cyclones originate on the western margins of the oceans. 3.? The release of latent heat helps in the rotation of tropical cyclone. 4. The highest velocity of winds is observed in the eye of the cyclone'.

A) 1, 2 and 3 only

B) 2, 3 and 4 only

C) 1, 2 and 4 only

D) 1, 2, 3 and 4

• A) The summer temperature never exceeds ${{25}^{o}}C$ between ${{10}^{o}}$ and ${{20}^{o}}S$ latitude.

B) The Coriolis Effect is weak.

C) There develops a high pressure area-on the western side of the South Atlantic.

D) The width of the ocean is not adequate enough for the development of cyclones.

• A) Large sea surface with temperature more than ${{27}^{o}}C$.

B) Pressure of coriol is force.

C) A pre-existing low pressure area.

D) Upper convergence above the sea level system.

•  List I List II A. Hurricanes?????? 1.? Coast of Florida B. Typhoons??????? 2.? Australia C. Willy-willies???? 3.? China D. Tornadoes?????? 4.? U.S.A.

A) 1 and 2 only

B) 2 and 3 only

C) 3 and 4 only

D) 1 and 4 only

• A) Type of tree grown in temperate regions.

B) Wind that blows in a desert.

C) Tropical cyclone of north-west Australia.

D) Kind of common fish found near Lakshadweep islands.

•  1. Tropical cyclones which hit the Florida coast are known as hurricanes. 2. Hurricanes cause large scale destruction in the area influenced by them. 3. Hurricanes contribute to the precipitation of the respective area. 4. Hurricanes flush out the pollutants from the water bodies.
Which of the above statements are correct?

A) 1, 2 and 3 only

B) 2, 3 and 4 only

C) 1, 2, 3 and 4

D) 1, 3 and 4 only

•  1. A tornado is a strong wind system fanned around an intensely low pressure system. 2. A tornado has a large diameter and is very destructive
Which of the above statements is/are correct?

A) 1 only

B) 2 only

C) Both 1 and 2

D) Neither 1 nor 2

• A) High pressure area surrounded by low pressure area.

B) Circular movement of air from centre to peripherals.

C) Direction of air is anticyclone.

D) They are mainly formed over the continents.

•  Assertion (A): Anti cyclonic conditions are found in winter season when atmospheric pressure is high and air temperatures are low. Reason (R): Winter rainfall in northern India causes development of anti-cyclonic conditions with low temperatures.

A) Both A and R is true and R is the correct explanation of A

B) Both A and R is true but R is not a correct explanation of A

C) A is true but R is false.

D) A is false but R is true.

•  Month Temperature ${{\mathbf{(}}^{\mathbf{o}}}\mathbf{C)}$ Rainfall (cm) January 3.9 4.7 February 4.4 5.7 March 8.3 8.2 April 14.4 9.2 May 20.0 9.2 June 23.3 17.7 July 27.8 14:5 August 27.8 14.0 September 22.3 12.7 October 18.3 7.0 November 12.2 5.0 December 6.7 3.5
These are most likely to be found in the natural region of

A) China type

B) Equatorial type

C) Hot desert type

D) Monsoon type

•  Month Temperature ${{(}^{\mathbf{o}}}\mathbf{C})$ Rainfall (cm) January 6.7 14.0 February 6.7 13.2 March 7.2 11.4 April 8.9 9.4 May 11.1 8.1 June 13.9 8.1 July 15.0 9.6 August 15.0 12.2 September 13.9 10.4 October 11.1 14.4 November 8.9 14.0 December 7.8 16.8
The climate to which this data pertains is

A) St Lawrence type

B) China type

C) West European type

D) Mediterranean type

•  1. In equatorial regions the year is divided into four main seasons. 2. In Mediterranean region, summers receive more rainfall. 3. In China type climate, rainfall occurs throughout the year. 4. Tropical highlands exhibit vertical zonation of different climates.
Which of these statements are correct?

A) 1, 2, 3 and 4

B) 1, 2 and 3 only

C) 1, 2 and 4 only

D) 3 and 4 only

•  1. Koppen believed that vegetation of an area is the best expression of totality of a climate. 2. Koppen's classification is based on the precipitation.
Which of the above statements is/are correct?

A) 1 only

B) 2 only

C) Both 1 and 2

D) Neither 1 nor 2

• A) A, B, C, D. E, F

B) A, B, C, E, H

C) A, B, C, E, H, W, T

D) A, B, C, D, E, H, S, W, T

•  1. In Koppen's classification of world climates, 'B' climate is based on precipitation while 'A' climate is based on rainfall. 2. 'C' climate has temperature above ${{18}^{o}}C$ throughout the year.
Which of the above statements is/are correct?

A) 1 only

B) 2 only

C) Both 1 and 2

D) Neither 1 nor 2

• A) Tropical rainfall

B) Tropical monsoon

C) Tropical desert

D) Tropical steppe

• A) Af

B) Am

C) Aw

D) None of these

• A) 'B' climates are based on the amount of rainfall.

B) 'A' climate has no month with temperature below ${{18}^{o}}C$

C) 'E' climates have average temperature of the warmest month above ${{10}^{o}}C$

D) 'BW' represents desert climate.

•  List I List II A. Af????? 1. Winter dry and very severe B. Aw???? 2. Dry hot summer, mild rainy winter C. Cs????? 3. Winter dry season D. Dw???? 4. No dry season

A) A-4, B-2, C-1, D-3

B) A-4, B-1, C-3, D-2

C) A-1, B-2, C-3, D-4

D) A-4, B-3, C-2, D-1

•  List I (Climate) List II (Area) A. Dfc??????????? 1. Canada B. BWh?????????? 2. Sahara C. Af???????????? 3. Amazon Basin D. EF???????????? 4. Greenland??

A) A-1, B-2, C-3, D-4

B) A-2, B-3, C-4, D-1

C) A-4, B-2, C-1, D-3

D) A-3, B-4, C-2, D-1

• A) Aw = Savanna

B) BW = Desert

C) Cs = Warm rainy with dry winter

D) Df= Cold climate with human winter and no dry season

•  1. Thom thwart?s classification of climate attempts to define the climate boundaries quantitatively. 2. Thom thwarts used precipitation and temperature to demarcate climate boundaries.
Which of the above statements is/are correct?

A) 1 only

B) 2 only

C) Both 1 and 2

D) Neither 1 nor 2

• A) Humidity zone A = Rainforest

B) Humidity zone B = Grassland

C) Humidity zone D = Steppe

D) Humidity zone E = Desert'

• A)

 List I (Temperature Province) List II (Climate) D'??????????????????????? 1.? Taiga

B)

 List I (Temperature Province) List II (Climate) ?F' ??????????????????????? 2.? Frost

C)

 List I (Temperature Province) List II (Climate) ?E'??????????????????? 3. Tundra

D)

 List I (Temperature Province) List II (Climate) ?B '?????????????????????? 4. Tropical

• A) Equatorial climate

B) Mediterranean climate

C) Monsoon climate

D) All of the above climates


text:
# 66392

## Автор(ов):

1

Параметры публикации

Тезисы доклада

## Название:

Stability of minimization problems and the error bound conditions in the Hilbert space

## Наименование конференции:

• International Conference "Approximation Theory and Applications" Dedicated to the 100th Anniversary S. B. Stechkin

## Наименование источника:

• Abstracts of talks on the International Conference “Approximation Theory and Applications” dedicated to the 100th anniversary of S. B. Stechkin

• Москва

• МГУ

2021

## Страницы:

4-4
Аннотация
We shall consider some sort of suﬃcient conditions ( the error bound conditions) for stability of the solution set for the problem min x \in A f(x) with respect to the function f (in C-norm) and with respect to the set A (in the Hausdorﬀ distance). Both the function and the set are nonconvex.

## Библиографическая ссылка:

Балашов М.В. Stability of minimization problems and the error bound conditions in the Hilbert space / Abstracts of talks on the International Conference “Approximation Theory and Applications” dedicated to the 100th anniversary of S. B. Stechkin. М.: МГУ, 2021. С. 4-4.

format: plain


text:
Find the equation of the line which passes through the point
Question:

Find the equation of the line which passes through the point $(3,-5)$ and cuts off intercepts on the axes which are equal in magnitude but opposite in sign.

Solution:

To Find: The equation of the line passing through (3, -5) and cuts off intercepts on the axes which are equal in magnitude but opposite in sign.

Given : Let a and b be two intercepts of $x$-axis and $y$-axis respectively.

According to the question $a=-b$ or $b=-a$

And $(3,-5)$ passes through the point $(x, y)$, thus satisfies the equation

Formula used:

Now since intercept form of the line is given by ,

$\frac{x}{a}+\frac{y}{b}=1$

$\frac{3}{a}+\frac{-5}{-a}=1$

$\frac{3+5}{a}=1$

$a=8$ and $b=-8$

Equation of the line is $\frac{x}{8}+\frac{y}{-8}=1$

$\Rightarrow$ Hence, the required equation of the line is $\frac{x}{8}-\frac{y}{8}=1 \Rightarrow x-y=8$

Administrator


text:
nLab cartesian functor

Contents

Context

Monoidal categories

monoidal categories

category theory

Contents

Definition

The phrase cartesian functor has been used in category theory with several different (but related) meanings.

Because of this ambiguity, it is perhaps always better to use a more precise term such as “(strong) morphism of fibrations”, “cartesian monoidal functor” or “finite product preserving functor”, and “finitely continuous functor” or “lex functor”.

Last revised on January 22, 2013 at 19:33:52. See the history of this page for a list of all contributions to it.


text:
## Chemistry: The Central Science (13th Edition)

The wavelength of the muon is $0.397nm$.
*The de Broglie relationship: $$\lambda=\frac{h}{mv}$$ $\lambda$: wavelength of object $h$: Planck's constant ($h=6.626\times10^{-34} J.s$) $m$: mass of object $v$: velocity of object 1) Find the known variables - Velocity of the muon: $v=8.85\times10^5cm/s=8.85\times10^3m/s$ 2) Calculate the mass of the muon - Mass of the electron: $9.109\times10^{-31}kg$ - Mass of the muon: $m=206.8\times(9.109\times10^{-31}kg)\approx1.884\times10^{-28}kg$ 3) Calculate the wavelength of the muon $\lambda=\frac{h}{mv}=\frac{6.626\times10^{-34}}{(1.884\times10^{-28})\times(8.85\times10^3)}\approx3.974\times10^{-10}m\approx0.397nm$


text:
The maximum value of the function $f(x)=-\dfrac{5}{3} x^3 +10x^2-15x+16$ in the interval $(0.5,3.5)$ is

1. $0$
2. $8$
3. $16$
4. $48$


text:
# Raised Scents Elite Selection

\$89.99
| /

Can't decide which scent you should get? Here is a package we have put together as an elite package to make sure you have everything you need. Having all of them creates all sorts of combinations you can try out, experiment with, or even use one specific scent whenever you want. On top of that, it's even at a discounted price! The package includes:

Buck Junkie Oil: Patent Pending Buck's forehead/salivary blend.

Scrape King Paste: Pure buck pre-orbital gland.

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Lonely Hot Doe Spray: Glandular scents from a doe in heat mixed with urine.

Scrape Addict Paste: Blend of 5 glands for mock scrapes.


text:
# How are Infinite sets compact?

A set is compact iff every open cover of the set has a finite subcover. Also, every set can be expressed as a union of singleton sets(which are open). So my question is how can a set containing infinite elements be compact ($[1,2]$ for an instance) considering the open cover consisting of singleton sets??

• If singletons are open, $[1,2]$ is not compact. – Hagen von Eitzen Oct 6 '17 at 17:17
• This is a category error. Sets cannot be compact, topological spaces may be. – Lord Shark the Unknown Oct 6 '17 at 17:17
• Yeah, in the usual topology, singletons are definitely not open. The topology matters. – Randall Oct 6 '17 at 17:18
• Sets can be compact in a given topology. $[0, 1]$ is compact in the usual topology on $\mathbb{R}$, but is clearly not in the discrete topology (the one where singletons are open). – Michael Lee Oct 6 '17 at 17:19
• Everyone is correct: a subset of a space is compact if and only if it is itself compact in its own subspace topology. – Randall Oct 6 '17 at 17:21

the open cover consisting of singleton sets

An open cover isn't just any old collection of sets which cover the given space - it's a collection of open sets which cover the given space. So when you say "the open cover consisting of singleton sets," you're assuming every singleton set is open.

This isn't true in general - e.g. in $\mathbb{R}$ with the usual topology, singletons are closed but not open. (In fact, "every singleton is open" is a very strong property - if $(X,\tau)$ is a space where every singleton is open, then every subset of $X$ is open in the sense of $\tau$.)

At this point it's worth being careful about what a topological space is, exactly. A topological space is a pair $(X,\tau)$ where

• $X$ is some set (like $\mathbb{R}$), and

• $\tau$ is a collection of subsets of $X$ (the "open sets") with a few properties ($\tau$ is closed under finite intersections, arbitrary unions, and we need $X,\emptyset\in\tau$).

Often when $\tau$ is obvious from context, we just talk about $X$ on its own - e.g. when we say "$(0, 1)$ is an open subset of $\mathbb{R}$" - but this is technically wrong! Instead, we should say something like "$(0,1)$ is an open subset of $\mathbb{R}$ with the Euclidean topology."


text:
# what is this current source

When we connect a resistor to current source a finite amount of current flows through it right? Okay but how is a closed path complete?I mean the current source has infinite resistance(I'm talking about ideal) so no current flows thorough it.it's like the circuit is open right?

• The ideal current source with it's infinte resistance is built with a battery with infinite voltage. – Kitana Nov 23 '14 at 19:36

When we say an ideal current source has infinite resistance, we are not talking about series resistance, we are talking about shunting resistance. The model of a non-ideal current source looks like this:

simulate this circuit – Schematic created using CircuitLab

In this diagram I labelled the resistor as "G" instead of "R" to emphasize that this is the dual of a voltage source, so it has a shunt conductor instead of a series resistor.

When we say an ideal current source has infinite resistance, we really should say it has 0 conductance, the dual of the ideal voltage source having 0 resistance.

simulate this circuit

And indeed, even if G is 0, there is a complete circuit. Current flows through the ideal current source, through the load, and back through the connection to the other terminal of the source.

If you are concerned that current can't flow through the current source because of Ohm's law, remember that Ohm's law isn't a law for all circuit elements, it's just a description of one type of element: the resistor. Current can also flow through other elements that have nothing to do with Ohm's law like capacitors, inductors, and sources.

Edit

This is to explain what I mean about circuit duality and why I bring it up.

First, in circuit theory neither the voltage source nor the current source is more fundamental than the other. Understanding both is necessary in order to model all circuits. For example, when doing transient analysis of circuits containing capacitors and inductors, the model of the capacitor at each timestep contains an ideal voltage source and the model of an inductor at each timestep contains an ideal current source. Even among practical circuits there are sources that are more straightforward to model as current sources than voltage sources: current mirrors and certain switching power supply configurations come to mind. We also use current sources to model the collector-emitter branch of a BJT in many cases.

Now, how does duality apply to this question?

You are probably already familiar with the voltage source, which looks like this:

And this model leads you to ask, if an ideal current source has infinite resistance, how can any current at all flow through it?

What you are missing is that when you talk about current sources, you are talking about the dual of the voltage source. And when you convert to the dual, you should convert series resistance to shunt conductance. This gives the current source model I showed above:

Notice that I didn't just replace the resistor with a conductor. I changed the circuit topology from series to parallel.

As you can see, in this dual device, when G goes to 0 (when the internal resistance is infinite) it does nothing at all to prevent current flowing through the source. It simply allows the ideal current source to deliver all of its value to the load, rather than having some shunted by its non-ideality element.

Just like how, by duality, in the voltage source when the non-ideality element (resistor) goes to 0, it allows all of the voltage to be delivered to the load.

• I'm not convinced. Your circuit is only the equivalent of a voltage source with a series resistor. When you set G to zero, then the current through a normal RL would be very low. That RL can see a constant current, independet of it's own value, G should have infinite resistance. And additionally in your circuit I is still an unexplained constant current source. An ideal current source can only be described with an infinite voltage source and an infinite resistor, but then the current is undefined. In reality you have to talk about active regulation and differential resistance. – Kitana Nov 23 '14 at 22:06
• I agree with @kitana - you are describing a current source with less than ideal quality. You aren't describing a current source in terms of a voltage source in series with a resistor. – Andy aka Nov 23 '14 at 22:34
• @Kitana, Nothing makes a voltage source more fundamental than a current source. You say, "An ideal current source can only be described with an infinite voltage source and an infinite resistor". I could equivalently say an ideal voltage source can only be described with an infinite current source and an infinite conductance. In fact, either one can be described with a single equation: either "V = Vs" or "I = Is". – The Photon Nov 23 '14 at 22:34
• @Andyaka, who says a current source has to be described as a voltage source with a series resistor? A current source and a voltage source are duals of each other. Neither one is necessarily constructed from the other one. – The Photon Nov 23 '14 at 22:35
• First off big thanks for the answers. But I too am not salsified with the explanation. An ideal current source is dual of ideal voltage source. Since voltage source has zero series resistance current source should have zero shunt resistance so....... – dushyanth Nov 24 '14 at 3:20

A perfect theoretical current source will drive it's current through an open circuit (if necessary) by self-adjusting the voltage at its output terminals to create thousands or millions of volts. Of course, in practise this is nonesense but who's talking about the real world?

This is why a theoretical current source is an infinite voltage divided by an infinite resistance (with the ratio of that infinite voltage to that infinite resistance being equal to the current it always supplies at its terminals).

It's not practical so don't lose sleep about it!

The internal resistance of a source can be determined by making two measurements. The voltage without any load and the short-circuit current. Dividing the two one gets the internal resistance. $$R_{i} = \frac {U_{s}}{I_{s}}$$ In real life it's often not advisable the make a short circuit, instead one makes the measurement with two different resistors and determines the change of the voltage and the current. $$r_{i} = \frac {\Delta U}{\Delta I}$$ The lowercase "r" indicates that it's a so called differential resistance. This differential resitance must no be the same over the whole operating range. Especially in extreme cases it will change.

With an ideal voltage source the voltage wouldn't change at all. $\Delta U$ and thus $r_{i}$ would be zero. Contrary an ideal current source would show no current change at all. Putting $\Delta I = 0$ in the formula above would give an error. $r_{i}$ is undefinded. Now there's a mathematical workaround for this problem, the "limit of a function". We make $\Delta I$ step by step smaller and look what happens with $r_{i}$. It becomes higher and higher, moving towards infinity. $$r_{i} = \lim_{\Delta I \to 0} \frac {\Delta U}{\Delta I} = \infty$$ Now we know why it's said that an ideal current source has infinite resistance.

In reality there are no ideal sources, infinite voltages or infinite currents, but the concept of an ideal source is very helpfull for calculations.

With modern electronics and active regulation, it's possible to build power supplies that come very close to these ideals - within determined boundaries. Real power supplies have a maximum for the voltage and the current that they can deliver. Below these limits they make a real good job.

• If we transform an ideal voltage source to current source it has 0 resistance in parallel to it. Which means no current flows through a resistance connected across the current source ( since current prefers less resistance path and 0 is the shortest resistance ). So what is happening here no current flows through a resistor connected across an 'IDEAL' current source. The less ideal it gets more is it's functionality. – dushyanth Nov 24 '14 at 14:22
• @dushyanth - Making the transformation you would get a current source with infinite current. Can someone then calculate the current through the load resistor? Once more it's obvious that such transformations applied on ideal sources make no sense. The use of ideal sources lies in modelling real sources, with real internal resistances, then you can apply those transformations. – Kitana Nov 24 '14 at 15:02


text:
# $a$ is a prime and $R$ is an integral domain $\implies a$ is irreducible

I noticed the following statement in a proof of a theorem on Euclidean rings.

$a$ is a prime and $R$ is an integral domain $\implies a$ is irreducible

It seems like this part of the statement is superfluous - $R$ is an integral domain.

Aren't primes always irreducible?

No, if the ring is not an integral domain, primes need not be irreducible. Consider $R = \mathbb{Z}/(6)$.

The elements $\overline{2}$ and $\overline{3}$ are prime, but you have $\overline{2} = \overline{2}\cdot \overline{4}$ and $\overline{3} = \overline{3}^2$, so they are not irreducible.

The most common definition is that a nonzero element $p$ is prime if it not invertible and, for all $a,b\in R$, $p\mid ab$ implies $p\mid a$ or $p\mid b$.

Every prime in an integral domain is irreducible: if $p$ is prime and $p=ab$, then either $p\mid a$ or $p\mid b$. If $p\mid b$, we have $b=px$ and so $p=apx$, so $ax=1$ and $a$ is invertible.

Note that the hypothesis that $R$ is an integral domain has been used when canceling $p$ from $p=apx$. If you add in the definition that $p$ is not a zero divisor, then the reasoning can go on in the same fashion.

No, a prime element need not be irreducible.

Recall that an element $x$ in a ring $R$ is prime if $\langle x\rangle$ is a prime ideal, ie if $R/\langle x\rangle$ is an integral domain.

For an example of a non-reducible prime, take the element $x = (1,0)$ in $R = \mathbb{F}_2\times \mathbb{F}_2$, which is not irreducible, since $x = x^2$ is a non-trivial factorization. But the quotient $R/\langle x\rangle$ is isomorphic to $\mathbb{F}_2$ and hence an integral domain.


text:
7 percent of fossil fuels consumed for non-combustion purposes

May 21, 2018 By

The U.S. Energy Information Administration (EIA) estimates that, while the majority of fossil fuels in the U.S. are burned, or combusted, to produce heat and power, the equivalent of about 5.5 quadrillion British thermal units of fossil fuels were consumed for non-combustion purposes in the U.S. in 2017.

Fossil fuels that are not combusted accounted for 7 percent of the total fossil fuel use in 2017. Image courtesy of the Energy Information Administration. Click to enlarge.

According to the EIA, over the past decade, non-combustion consumption of fossil fuels has typically accounted for about 7 percent of total fossil fuel consumption and about 6 percent of total energy consumption in the U.S. Fossil fuels can be consumed, but not combusted, when they are used directly as construction materials, chemical feedstocks, lubricants, solvents, waxes and other products.

In 2017, about 13 percent of total petroleum products consumed were for non-combustion use, the EIA reports. Natural gas non-combustion use accounted for about 3 percent of total natural gas, while coal was less than 1 percent.

In 2017, carbon dioxide (CO2) emissions would have been 196 metric tons (about 4 percent) higher if non-combustion fuel use would have been combusted, the EIA says. The estimation of fossil fuels for non-combustion consumption is essential to calculate total U.S. CO2 emissions. According to the EIA, in the non-combustion of these fuels, some of the carbon is sequestered and not included in the fuel consumption values for emissions calculations.

Petroleum products account for about 86 percent of non-combustion consumption, the EIA reports. Hydrocarbon gas liquids are an important component for making plastics, while petrochemical feedstocks are used directly at chemical plants and to make synthetic fabric, synthetic rubbers, detergents and other chemical products.

Petroleum products account for 86 percent of all non-combustion consumption. Photo courtesy of The U.S. Energy Information Administration. Click to enlarge.

Petroleum products are also consumed for non-combustion purposes such as roofing and paving construction; vehicle and machinery lubricants; and as chemical catalysts. Other petroleum products include distillate and residual fuel oils used as chemical feedstocks as well as polishes and waxes, the EIA says.

Small amounts of natural gas are used in the industrial sector and as a feedstock to make nitrogenous fertilizers and a range of chemical products, including ammonia, hydrogen and methanol.

Small amounts of coal are used for non-combustion purposes. According to the EIA, among the byproducts of the process to produce metallurgical coke are coal tars, which are rich in aromatic hydrocarbons, such as benzene, and are used as feedstocks in the chemical industry to make sealcoats for pavement, synthetic dyes and paints. Additionally, some anti-dandruff shampoos and other medical skin care products contain coal tars.

About the Author: Clara Richter

Clara Richter is the managing editor at LP Gas magazine. Contact her at crichter@northcoastmedia.net or 216-363-7920.

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