Daily quizz questions( 10)

4 July 2026

Daily quizz questions( 10)

Consider the following statements regarding the Coriolis force:

It is zero at the equator and maximum at the poles.

It acts perpendicular to the direction of wind flow.

It deflects winds to the left in the Northern Hemisphere.Daily quizz questions

Which of the statements given above is/are correct?

(a) 1 and 2 only

(b) 2 only

(c) 1, 2 and 3

(d) 3 only

Answer: (a)

— Statement 3 is wrong; deflection is to the

right

in the Northern Hemisphere (Ferrel’s Law).Coriolis force

The ‘Ring of Fire’ is associated with which of the following?

(a) Mid-Atlantic Ridge volcanic activity

(b) Seismic and volcanic activity around the Pacific Ocean margins

(c) Coral reef distribution in the Indian Ocean

(d) Rift valley formation in East Africa

Answer: (b)

With reference to Indian rivers, consider the following pairs:

Chambal — tributary of Yamuna

Son — tributary of Ganga

Gandak — tributary of Brahmaputra

Which of the pairs given above is/are correctly matched?

(a) 1 only

(b) 1 and 2 only

(c) 2 and 3 only

(d) 1, 2 and 3

Answer: (b)

— Gandak is a tributary of the Ganga, not the Brahmaputra.

Surha Taal: India’s 100th Ramsar Site

Which of the following best explains the formation of ‘Loess’ plains?

(a) Deposition of volcanic ash over millions of years

(b) Wind-blown deposition of fine silt, largely from glacial outwash and deserts

(c) Alluvial deposition by braided rivers

(d) Chemical weathering of limestone

Answer: (b)

— Classic example: the Loess Plateau of China.

The Tropic of Cancer does NOT pass through which of the following Indian states?

(a) Chhattisgarh

(b) Jharkhand

(c) Odisha

(d) Tripura

Answer: (c)

— It passes through Gujarat, Rajasthan, MP, Chhattisgarh, Jharkhand, WB, Tripura, and Mizoram — not Odisha.

Consider the following statements about El Niño:

It refers to abnormal warming of surface waters in the eastern tropical Pacific Ocean.

It is typically associated with weaker Indian monsoons.

La Niña has effects opposite to El Niño.

Which of the statements given above are correct?

(a) 1 and 2 only

(b) 2 and 3 only

(c) 1 and 3 only

(d) 1, 2 and 3

Answer: (d)

Which of the following straits connects the Arabian Sea with the Persian Gulf?

(a) Strait of Malacca

(b) Strait of Hormuz

(c) Bab-el-Mandeb

(d) Palk Strait

Answer: (b)

The phenomenon of ‘temperature inversion’ is most pronounced under which of the following conditions?

(a) Cloudy nights with high wind speed

(b) Clear nights, calm air, and long winter nights

(c) Daytime with high humidity

(d) Coastal areas during monsoon

Answer: (b)

— Common in valleys and basins like Kashmir and Siberia.

With reference to India’s soil types, ‘Regur soil’ is characterized by which of the following?

High moisture retention capacity

Rich in iron and calcium, poor in nitrogen and phosphorus

Formed from the weathering of granite and gneiss

Select the correct answer using the code below:

(a) 1 and 2 only

(b) 2 and 3 only

(c) 1 and 3 only

(d) 1, 2 and 3

Answer: (a)

— Regur (black cotton soil) forms from weathered lava/basaltic rock, not granite/gneiss.

10.

Which of the following best describes ‘Antarctic Circumpolar Current’?

(a) A warm current flowing along the eastern coast of Antarctica

(b) The only ocean current that flows completely around the globe, driven by strong westerly winds

(c) A seasonal current linked to Antarctic sea-ice melting only

(d) A current confined to the Weddell Sea

Answer: (b)

EXPLANATION

What is the Coriolis Force?,Daily quizz questions

The Coriolis force is an

apparent (pseudo) force

that acts on any object moving over the surface of a rotating Earth. It doesn’t actually push or pull anything in the real sense — it’s an effect we observe because we’re measuring motion from a rotating frame of reference (the Earth), while the object is actually moving in a straight line relative to space.

It was first mathematically described by French scientist

Gaspard-Gustave de Coriolis

in 1835.

Why Does It Occur?

The Earth rotates faster (in terms of linear velocity) at the equator than near the poles, because a point on the equator has to cover a much larger circumference in the same 24 hours compared to a point near the poles.

At the

equator

: linear velocity ≈ 1,670 km/hr

At the

poles

: linear velocity ≈ 0 km/hr

When a parcel of air or water moves from one latitude to another, it carries its original speed of rotation with it. This mismatch between the object’s momentum and the speed of the surface beneath it causes an

apparent

deflection.

Let me show you how this deflection works:

The Deflection Rule (Ferrel’s Law)

This gives us

Ferrel’s Law

:

Northern Hemisphere

→ moving objects (wind, ocean currents, missiles) deflect to the

right

of their path.

Southern Hemisphere

→ they deflect to the

left

At the equator

→ the Coriolis force is effectively

zero

, since there’s no rotational component perpendicular to motion there.

The magnitude of deflection is

directly proportional to the sine of latitude

and the

speed of the moving object

— it’s zero at the equator, maximum at the poles, and stronger for fast-moving bodies (like jet streams) than slow ones.

Why It Matters in Geography

1. Wind Systems

The Coriolis force is why trade winds, westerlies, and polar easterlies don’t blow in straight north-south lines but curve. It’s essential to forming the global pressure belt and wind system.

2. Cyclones and Anticyclones

In the Northern Hemisphere, cyclones (low pressure) rotate

counterclockwise

, and anticyclones rotate

clockwise

In the Southern Hemisphere, it’s the reverse.

This is entirely due to the Coriolis effect acting on air converging toward or diverging from a pressure center.

3. Ocean Currents

Major ocean gyres — like the clockwise North Atlantic Gyre and counterclockwise South Atlantic Gyre — owe their rotational direction to Coriolis deflection acting on surface currents (Ekman spiral is a related concept worth knowing).

4. Ekman Spiral

As wind drags surface ocean water, the Coriolis force causes each successive layer of water below to be deflected further, creating a spiral pattern with depth — net water transport occurs at 90° to the wind direction.

Key UPSC Points to Remember

Aspect

Detail

Also called

Ferrel’s Law / Geostrophic force

Zero at

Equator

Maximum at

Poles

NH deflection

Right

SH deflection

Left

Formula factor

Proportional to 2Ω·sin(φ)·v (Ω = angular velocity, φ = latitude, v = velocity)

Does NOT depend on

Direction of wind’s original motion (deflects regardless of initial bearing)

Common Misconceptions (Exam Traps)

❌ “Coriolis force

causes

wind” — No, pressure gradient force initiates wind; Coriolis only

deflects

it.

❌ “It’s strongest at the equator” — Reverse is true.

❌ “It affects bathtub drains” — This is a popular myth; the effect is far too weak at that scale to matter (a common distractor in prelims)

Ring of fire

The

Ring of Fire

(also called the

Circum-Pacific Belt

) is a horseshoe-shaped zone stretching roughly 40,000 km around the margins of the Pacific Ocean. It is the most seismically and volcanically active region on Earth.

Extent

It runs along the coasts of:

South America

(Andes)

Central America and Mexico

Western United States and Canada

(Cascade Range, Alaska)

Aleutian Islands

Kamchatka Peninsula and Japan

Philippines, Indonesia

New Zealand and the South Pacific islands

Why It Exists — The Tectonic Mechanism

The Ring of Fire is a direct consequence of

plate tectonics

, specifically the boundaries of the

Pacific Plate

with several surrounding plates (Nazca, Cocos, North American, Philippine, Indo-Australian, and Juan de Fuca plates).

Most of this zone consists of

convergent plate boundaries

, where a denser oceanic plate is forced beneath a lighter continental or oceanic plate — a process called

subduction

Let me show you how this subduction mechanism drives both volcanism and earthquakes:

What Happens at These Boundaries

1. Subduction and Volcanism

As the oceanic plate descends into the mantle, it heats up and releases water into the surrounding mantle rock. This lowers the melting point of the rock above, generating magma that rises to the surface — forming chains of

stratovolcanoes

(composite volcanoes), such as those in the Andes, Japan, and Indonesia.

2. Earthquakes

The friction between the subducting and overriding plates builds up enormous stress. When this stress is released suddenly, it produces earthquakes — often at increasing depths as you move inland from the trench (a pattern called the

Wadati-Benioff zone

3. Oceanic Trenches

Where subduction begins, deep linear depressions called

trenches

form — including the

Mariana Trench

, the deepest point on Earth (~11,000 m), located in the western Pacific.

4. Island Arcs

Where oceanic plate subducts beneath oceanic plate, volcanic

island arcs

form — e.g., Japan, the Philippines, the Aleutians, and Indonesia.

Key Statistics (UPSC-Relevant)

Fact

Detail

~90% occur along the Ring of Fire

~75% of active/dormant volcanoes located here

Length

~40,000 km

Major plates involved

Pacific, Nazca, Cocos, Juan de Fuca, Philippine, Indo-Australian, North American

Deepest trench

Mariana Trench

Notable disasters

2004 Sumatra earthquake/tsunami, 2011 Tōhoku earthquake (Japan), Krakatoa and Mt. Pinatubo eruptions

Important Exceptions/Nuances for Exams

Not the entire ring is subduction — a portion in California follows the

San Andreas Fault

, which is a

transform boundary

(plates sliding past each other), not a convergent one. This is a classic UPSC distractor.

The mid-oceanic ridges (divergent boundaries) are

not

part of the Ring of Fire — the Ring is specifically about the

margins

of the Pacific, not its center.

Countries like

Chile, Japan, Indonesia, and the Philippines

are prime examples of nations built almost entirely along this active zone, making disaster preparedness a major geographic and policy concern there.

Here are detailed explanations for questions 3 through 10 from the original quiz:

Q3. Indian River Tributaries

The correct answer is

(b) 1 and 2 only

Chambal → Yamuna

: Correct. The Chambal originates near Mhow in Madhya Pradesh and flows northeast to join the Yamuna in Uttar Pradesh. It’s known for its ravines and is also home to the Chambal Wildlife Sanctuary (gharials, dolphins).

Son → Ganga

: Correct. The Son originates in the Amarkantak Plateau (same region as the Narmada) and joins the Ganga near Patna, Bihar.

Gandak → Brahmaputra

:

Incorrect

. The Gandak (also called Narayani in Nepal) originates in the Nepal Himalayas and joins the

Ganga

, not the Brahmaputra, near Patna, Bihar. This is a classic examiner trick — pairing a correct river with the wrong main stem.

Tip:

Remember that most north Indian tributaries (Gandak, Kosi, Ghaghara, Son, Chambal, Yamuna) ultimately join the

Ganga

, while the Brahmaputra’s major tributaries are different (Dibang, Lohit, Subansiri, Manas, Teesta).

Q4. Loess Plains

The correct answer is

(b)

Loess

is a fine-grained, wind-deposited (aeolian) sediment. It typically originates from:

Glacial outwash plains, where meltwater deposits fine rock flour

Desert regions, where strong winds pick up fine silt and transport it over long distances

The classic example is the

Loess Plateau of China

, formed by winds carrying silt from the Gobi Desert over thousands of years. This soil is extremely fertile but also highly erodible, making it prone to gully formation and landslides — an important reason it’s frequently tested.

Why not the others:

Volcanic ash deposition forms different soils (like Regur/black soil in some contexts); alluvial deposition by rivers forms floodplains, not loess; chemical weathering of limestone produces terra rossa or karst features, unrelated to loess.

Q5. Tropic of Cancer and Indian States

The correct answer is

(c) Odisha

The Tropic of Cancer (23°30′ N) passes through exactly

8 Indian states

, in order from west to east:

Gujarat → Rajasthan → Madhya Pradesh → Chhattisgarh → Jharkhand → West Bengal → Tripura → Mizoram

Odisha lies entirely

south

of this line, so it is correctly excluded.

Mnemonic:

“Gujarat Rajasthan Mein Chai Jharkhand Wale Tripura Mein” (a common trick to remember the 8 states in sequence).

Q6. El Niño

The correct answer is

(d) all three statements are correct

Statement 1

: El Niño is characterized by abnormal warming of sea surface temperatures in the central and eastern tropical Pacific Ocean, disrupting the normal Walker Circulation.

Statement 2

: This warming weakens the pressure gradient that normally drives the Indian monsoon winds, often leading to

below-normal monsoon rainfall

in India (though the correlation isn’t perfect — some El Niño years have had normal monsoons).

Statement 3

: La Niña is essentially the opposite phase — abnormal

cooling

of the same Pacific waters — and it typically strengthens the Indian monsoon.

UPSC angle:

This ENSO (El Niño-Southern Oscillation) cycle is a favorite topic connecting oceanography, climatology, and Indian agriculture/economy.

Q7. Strait of Hormuz

The correct answer is

(b)

The

Strait of Hormuz

connects the

Persian Gulf

to the

Gulf of Oman

and then the

Arabian Sea

. It lies between Iran and Oman (Musandam Peninsula) and is one of the world’s most strategically important chokepoints, since a significant share of global oil exports passes through it.

Why not the others:

Strait of Malacca

: connects the Indian Ocean to the South China Sea (between Malaysia/Indonesia)

Bab-el-Mandeb

: connects the Red Sea to the Gulf of Aden (Arabian Sea)

Palk Strait

: separates India (Tamil Nadu) from Sri Lanka

Tip:

Chokepoints/straits are a recurring UPSC theme, often linked to geopolitics and energy security.

Q8. Temperature Inversion

The correct answer is

(b)

Temperature inversion is an atmospheric condition where temperature

increases with height

instead of the normal decrease. It occurs best under:

Clear skies

(no clouds to trap outgoing radiation, so the ground loses heat rapidly at night)

Calm air

(no wind to mix warmer and cooler air layers)

Long winter nights

(more time for the ground to radiate away heat before sunrise)

This is why places like

Jammu & Kashmir valleys

,

Siberia

, and hill stations often experience severe cold and fog in winter mornings — the coldest, densest air settles at the bottom of valleys.

Why not the others:

Cloudy, windy nights prevent the necessary radiative cooling and mixing conditions; daytime humidity and coastal monsoon conditions don’t create the still, radiative-cooling setup inversion needs.

Q9. Regur Soil (Black Cotton Soil)

The correct answer is

(a) 1 and 2 only

Statement 1

: Correct. Regur soil has high clay content, giving it excellent moisture retention — which is why it’s ideal for cotton cultivation even in low-rainfall regions like the Deccan Plateau.

Statement 2

: Correct. It’s rich in iron, magnesium, and calcium carbonate (giving it a blackish color from titaniferous magnetite), but poor in nitrogen, phosphorus, and organic matter.

Statement 3

:

Incorrect

. Regur soil forms from the weathering of

basalt and lava rock

(Deccan Trap volcanic rock), not granite or gneiss. Granite/gneiss weathering typically produces

red soil

Key distinction for exams:

Black soil = basaltic/volcanic origin (Maharashtra, MP, Gujarat, parts of AP/Telangana); Red soil = granite/gneiss origin (Tamil Nadu, Karnataka, parts of Odisha/Chhattisgarh).

Q10. Antarctic Circumpolar Current (ACC)

The correct answer is

(b)

The ACC is the

only ocean current that flows completely around the globe

without interruption by any continental landmass, because it circles Antarctica in the Southern Ocean where no land blocks its path. It’s driven by the powerful, persistent

westerly winds

(“Roaring Forties,” “Furious Fifties,” “Screaming Sixties”).

It plays a critical role in:

Isolating Antarctica thermally, helping maintain its ice sheets

Connecting and mixing waters of the Atlantic, Pacific, and Indian Oceans

Global thermohaline circulation (the “ocean conveyor belt”)

Why not the others:

It’s not confined to the Weddell Sea (that’s a regional gyre within the Southern Ocean), it’s not warm (Antarctic waters are cold), and its existence is a year-round structural feature, not a seasonal melt-driven phenomenon.