All practice questions

Question 12281Question →

In a community with a total population of $50,000$ , a local demographic survey recorded $1,250$ live births in one year. What is the Crude Birth Rate (CBR) per $1,000$ population for this community?

Show answer & explanation

Answer: 25

Answer

The Crude Birth Rate is 25 per 1,000 population.

The Crude Birth Rate is calculated by dividing total live births (

1,250

) by total population (

50,000

) and multiplying by

1,000

, resulting in

25

per

1,000

population.

Step-by-Step Solution

1

Identify the formula for calculating Crude Birth Rate (CBR).

\text{CBR} = \frac{\text{Total Live Births}}{\text{Total Population}} \times 1,000

.

Crude Birth Rate is defined as the number of live births per 1,000 people in a given population in a year.

2

Substitute the given values into the equation and solve.

\text{CBR} = \frac{1,250}{50,000} \times 1,000 = 25

.

Dividing

1,250

by

50,000

gives

0.025

, and multiplying by

1,000

yields

25

.

Key Concept

Crude Birth Rate Calculation

Question 12282Question →

Match each rock listed in Column I with its correct classification, characteristic texture, or primary economic application in Column II.

Click a left item, then click its matching right item

Show answer & explanation

Answer

Obsidian matches with the extrusive igneous rock with a glassy texture; Gypsum matches with the chemical sedimentary rock formed by evaporation used for plaster of Paris; Anthracite matches with the high-rank organic metamorphic rock used as fuel; Quartzite matches with the hard, non-foliated metamorphic rock derived from quartz sandstone.

Each rock is paired accurately according to its genetic rock family and physical/economic properties: Obsidian is a glassy extrusive igneous rock, Gypsum is an evaporite chemical sedimentary rock used in construction, Anthracite is an organic metamorphic coal with high heat value, and Quartzite is a durable metamorphic rock derived from sandstone.

Step-by-Step Solution

1

Identify the origin and texture of Obsidian.

Obsidian is volcanic glass formed by rapid cooling of lava without crystallization.

Rapid surface cooling prevents mineral crystals from forming.

2

Identify the formation process and economic use of Gypsum.

Gypsum is a chemical evaporite used in building materials like plaster of Paris.

Evaporation leaves behind calcium sulfate deposits.

3

Identify the classification and composition of Anthracite.

Anthracite is metamorphosed organic material rich in carbon.

Heat and pressure transform peat/lignite into hard metamorphic coal.

4

Identify the parent rock and resistance of Quartzite.

Quartzite is formed from quartz sandstone via recrystallization.

Metamorphism locks quartz mineral grains into a dense interlocking matrix.

Key Concept

Rock Types, Formation, and Economic Importance

Question 12283Question →

The bookkeeper of Folake Stores extracted the following balances from the ledger accounts at the end of the financial year:

Account Title	Balance (₦)
Purchases	$280,000$
Sales	$450,000$
Capital	$200,000$
Rent Expense	$35,000$
Salaries	$65,000$
Motor Vehicles	$180,000$
Trade Debtors	$90,000$
Trade Creditors	$75,000$
Cash at Bank	$75,000$

What is the total of the debit column in the Trial Balance extracted by the bookkeeper?

₦690,000

₦725,000

��800,000

₦895,000

Show answer & explanation

Answer: $₦725,000$

Answer

₦725,000

The debit column of a trial balance consists of assets, expenses, and purchases. Adding Purchases (

₦280,000

), Rent Expense (

₦35,000

), Salaries (

₦65,000

), Motor Vehicles (

₦180,000

), Trade Debtors (

₦90,000

), and Cash at Bank (

₦75,000

) gives a total of

₦725,000

.

Step-by-Step Solution

1

Identify all ledger accounts that carry normal debit balances (Assets and Expenses)

Debit items are Purchases (

₦280,000

), Rent Expense (

₦35,000

), Salaries (

₦65,000

), Motor Vehicles (

₦180,000

), Trade Debtors (

₦90,000

), and Cash at Bank (

₦75,000

).

According to double-entry rules, asset and expense accounts maintain debit balances.

2

Sum the balances of all debit items

280,000 + 35,000 + 65,000 + 180,000 + 90,000 + 75,000 = 725,000

To calculate the total debit column in the trial balance.

Key Concept

Classification of Ledger Balances in a Trial Balance

Question 12284Question →

In a historical highland district characterized by defensive hilltop clustering due to past inter-tribal conflicts, the construction of a major arterial road through the adjacent lowland valley prompted widespread downhill migration of agricultural households. Which spatial transformation best describes the structural evolution of this rural settlement pattern over time?

Transition from a nucleated pattern on the heights to a linear pattern aligned with the valley highway

Shift from a dispersed layout on the ridge to a ring-shaped settlement surrounding lowland agricultural fields

Evolution from a linear hilltop arrangement to a compact nucleated node isolated from the transport corridor

Movement driven by environmental push factors into a fragmented, randomly dispersed pattern across the valley floor

Show answer & explanation

Answer: Transition from a nucleated pattern on the heights to a linear pattern aligned with the valley highway

Answer

Transition from a nucleated pattern on the heights to a linear pattern aligned with the valley highway

Historically, defensive requirements and terrain constraints on hilltops forced rural homesteads to cluster tightly into nucleated settlement patterns. When regional peace was established and a major transport artery was built through the valley floor, economic pull factors—such as access to trade, mobility, and markets—encouraged population movement off the hills. As houses were built along the new highway, the settlement structure evolved into a classic linear pattern.

Step-by-Step Solution

1

Analyze the initial physical site and historical context of the rural settlement

Defensive requirements on elevated hilltops naturally constrain space and promote tight clustering, producing a nucleated settlement pattern.

Security concerns during historical conflicts forced homesteads to concentrate in defensible locations.

2

Evaluate the impact of changing economic and infrastructural factors (opening of the highway)

The road provides accessibility to markets, services, and trade, serving as a powerful economic pull factor.

Modern rural settlements prioritize transport accessibility over historical defensive isolation.

3

Determine the resulting spatial arrangement along the new transport axis

Buildings expand parallel to the highway, creating a continuous linear settlement pattern.

Linear settlement patterns characteristically develop along major lines of communication such as roads, rivers, and railways.

Key Concept

Morphogenetic evolution of rural settlements from defensive nucleated hill-sites to linear transport-oriented lowlands

Estimated Time:2m 0s

Question 12285Question →

Environmental conservation is governed by core principles that distinguish it from total preservation and unmitigated exploitation. Which of the following statements best evaluates the primary underlying need for environmental conservation in modern resource management?

To ensure the planned and sustainable utilization of natural resources so that present economic needs are met without compromising ecological stability for future generations.

To completely prohibit human entry and resource extraction across all ecosystems, viewing all natural elements as non-renewable assets that must remain undisturbed.

To maximize the immediate extraction rate of exhaustible resources while deferring environmental baseline assessments to post-project decommissioning stages.

To restrict environmental management exclusively to reactive cleanup protocols following acute oil spills and industrial disasters rather than preventive regulation.

Show answer & explanation

Answer: To ensure the planned and sustainable utilization of natural resources so that present economic needs are met without compromising ecological stability for future generations.

Answer

The primary underlying need for environmental conservation is to ensure the planned and sustainable utilization of natural resources so that present economic needs are met without compromising ecological stability for future generations.

The correct answer accurately states the dual objective of environmental conservation: managing and utilizing natural resources rationally to meet current human requirements while maintaining environmental equilibrium and resource availability for future generations.

Step-by-Step Solution

1

Define the concept of environmental conservation

Environmental conservation refers to the rational management, protection, and wise utilization of natural resources to prevent degradation and depletion.

Establishing the precise definition distinguishes conservation from total preservation or unmitigated exploitation.

2

Analyze the core necessity (why conservation is required)

Human dependence on natural systems for survival and economic development necessitates a balance between consumption and replenishment.

Without planned management, finite resources face exhaustion and renewable resources lose their regenerative capacity.

3

Evaluate the options against sustainable development principles

The statement emphasizing planned and sustainable resource use to safeguard future generations correctly reflects the core intent of environmental conservation.

Sustainable resource management fulfills current human needs while ensuring long-term ecological balance.

Key Concept

Concept and Need for Environmental Conservation

Estimated Time:1m 30s

Question 12286Question →

Which of the following atmospheric mechanisms is primarily responsible for the progressive northward decrease in mean annual precipitation and wet season duration across Nigeria?

The reduced penetration duration and shallowing depth of the moist Maritime Tropical air mass away from the coast

The steep increase in general land elevation across the High Plains of Hausaland forcing cold air subsidence

The seasonal reversal of coastal ocean currents in the Gulf of Guinea during the summer months

The obstruction of North-East Trade winds by the Jos Plateau creating a rain-shadow zone over northern states

Show answer & explanation

Answer: The reduced penetration duration and shallowing depth of the moist Maritime Tropical air mass away from the coast

Answer

The reduced penetration duration and shallowing depth of the moist Maritime Tropical air mass away from the coast

Nigeria's rainfall regime is dictated by the movement of the Inter-Tropical Discontinuity (ITD), which represents the surface boundary between the moist Maritime Tropical (mT) air mass from the Atlantic and the dry Tropical Continental (cT) air mass from the Sahara. Because southern Nigeria is closest to the ocean source, it stays beneath a deep layer of mT air for most of the year, resulting in high annual rainfall and a long wet season. As the mT air moves inland towards the north, its vertical depth decreases and its duration becomes much shorter, driving the progressive reduction in rainfall.

Step-by-Step Solution

1

Identify the primary air mass bringing rainfall to Nigeria

The Maritime Tropical (

mT

) air mass originating over the Atlantic Ocean carries moisture inland.

Rainfall in West Africa is driven by the northward advance of moist marine air.

2

Analyze how air mass movement determines seasonal duration along the latitudinal gradient

Southern Nigeria experiences the influence of the humid

mT

air mass for up to 9–12 months, whereas extreme northern Nigeria receives this air mass for only 3–4 months.

The Inter-Tropical Discontinuity (

ITD

) reaches its northernmost position around July/August and retreats rapidly southward.

3

Relate air mass depth to total annual precipitation

Because the moisture layer thins and stays for a shorter duration farther north, total annual rainfall steadily decreases from south (

>3000\text{ mm}

) to north (

<600\text{ mm}

).

Precipitation volume depends directly on air mass thickness and residence time.

Key Concept

Air Mass Dynamics and ITD Movement in Nigeria

Estimated Time:1m 0s

Question 12287Question →

Match each Earth structural layer or atmospheric zone listed in Column I with its correct physical or compositional characteristic in Column II.

Click a left item, then click its matching right item

Show answer & explanation

Answer

Asthenosphere matches with the semi-fluid upper mantle layer; Barysphere matches with the dense iron-nickel central core; Atmospheric Mesosphere matches with the atmospheric layer above the stratosphere where temperature decreases with altitude; Sialic Crust matches with the upper continental granitic layer rich in silica and aluminium.

The matching pairs reflect true geological and atmospheric definitions: the Asthenosphere is the ductile upper mantle region driving plate dynamics, the Barysphere is the central dense core, the Atmospheric Mesosphere is the thermal region above the stratosphere where temperature decreases with height, and the Sialic Crust is the granitic continental layer.

Step-by-Step Solution

1

Analyze the physical properties of the internal structural layers of the Earth.

The asthenosphere is a ductile zone within the upper mantle, the barysphere is the dense inner metallic core, and the sialic crust forms the upper continental layer rich in silica and aluminium.

Different internal Earth zones are differentiated by density, mineral composition, and rheology.

2

Analyze the physical characteristics of the external sphere (atmospheric mesosphere).

The atmospheric mesosphere is situated above the stratosphere and experiences a steady temperature decline with increasing altitude.

External atmospheric layers are categorized by thermal structure and environmental properties.

3

Match each structural item in Column I to its accurate defining characteristic in Column II.

Each layer is accurately paired to its specific chemical composition or mechanical behavior.

Verification confirms no overlap or misattribution among structural boundaries.

Key Concept

Internal and External Structure of the Earth

Question 12288Question →

The River Niger exhibits a unique hydrological regime featuring a vast inland delta (the Macina) in Mali, where severe transmission losses occur due to high evapotranspiration and seepage in the semi-arid Sahel. Which of the following hydrological factors is primarily responsible for sustaining its downstream volume as it flows through Niger Republic and into Nigeria?

The seasonal flood surge generated by heavy summer monsoon rains in its humid headwaters in the Fouta Djallon highlands, augmented by the influx of the Bani River.

Subterranean seepage and direct overflow discharging westward from the Lake Chad endorheic basin into the upper Benue River.

High-altitude snowmelt and torrential upper-course tributaries originating from the Ahaggar and Tibesti mountain massifs.

Continuous subterranean inflow from the Nile River catchment moving westward across the Sudanian zone into the Niger basin.

Show answer & explanation

Answer: The seasonal flood surge generated by heavy summer monsoon rains in its humid headwaters in the Fouta Djallon highlands, augmented by the influx of the Bani River.

Answer

The River Niger's flow into its middle and lower courses is sustained by the seasonal flood surge originating from heavy summer monsoon rainfall in the Fouta Djallon highlands of Guinea, combined with significant tributary inflow from the Bani River.

The upper River Niger originates in the high-rainfall Fouta Djallon plateau of Guinea, receiving heavy monsoonal precipitation. This generates a massive seasonal flood wave. As the river enters Mali, the Bani River contributes critical additional volume before the main flow enters the Macina inland delta, allowing sufficient water to survive extreme evaporative losses and sustain the middle and lower river courses.

Step-by-Step Solution

1

Analyze the hydrological behavior of the River Niger across its distinct course sections.

Identified that the upper course receives tropical monsoonal rainfall in the humid Fouta Djallon highlands, initiating a major annual flood wave.

Understanding headwater climatic controls explains how large volumes of water enter the system before reaching arid zones.

2

Examine the effect of the Macina inland delta on river discharge.

Recognized that while the Macina causes substantial water loss via evaporation and infiltration, the primary flood wave takes months to navigate the wetland.

Explains why a delayed secondary high-water peak (the 'black flood') emerges downstream in Niger and Nigeria during the dry season.

3

Evaluate the role of major tributaries in maintaining flow south of the inland delta.

Determined that the Bani River joins the Niger at Mopti, adding substantial volume drained from the humid southern savanna zone.

Confirms the primary hydrological mechanism sustaining downstream discharge into its middle course.

Key Concept

Hydrological regimes and discharge characteristics of major African rivers

Question 12289Question →

A proposed rural electrification line connecting a community to a regional substation measures $15.6\text{ cm}$ on a topographical map drawn to a Representative Fraction (R.F.) scale of $1 : 50,000$ . What is the actual length of the power line on the ground in kilometers?

3.12\text{ km}

7.8\text{ km}

15.6\text{ km}

78.0\text{ km}

Show answer & explanation

Answer: $7.8\text{ km}$

Answer

7.8\text{ km}

The Representative Fraction scale of

1 : 50,000

indicates that

1\text{ cm}

on the map represents

50,000\text{ cm}

(

0.5\text{ km}

) on the ground. Multiplying the map distance of

15.6\text{ cm}

by

0.5\text{ km/cm}

gives the actual ground distance of

7.8\text{ km}

.

Step-by-Step Solution

1

Calculate total ground distance in centimeters using the R.F. scale

15.6\text{ cm} \times 50,000 = 780,000\text{ cm}

An R.F. scale of

1 : 50,000

means

1\text{ unit}

on the map equals

50,000\text{ units}

on the ground.

2

Convert centimeters to kilometers

\frac{780,000\text{ cm}}{100,000\text{ cm/km}} = 7.8\text{ km}

There are

100,000\text{ centimeters}

in

1\text{ kilometer}

.

Key Concept

Map Scale Distance Calculation

Estimated Time:1m 30s

Question 12290Question →

A survey map of a proposed cocoa plantation in southwestern Nigeria is drawn to a scale of $1 : 50,000$ . If the main access road across the plantation measures $12\text{ cm}$ on the map, what is the actual ground distance of the road in kilometers?

Show answer & explanation

Answer: 6

Answer

The actual ground distance of the road is

6\text{ km}

.

To determine the actual ground distance, multiply the measured map distance (

12\text{ cm}

) by the scale denominator (

50,000

) to get

600,000\text{ cm}

. Converting this value into kilometers by dividing by

100,000

gives an actual ground distance of

6\text{ km}

.

Step-by-Step Solution

1

Calculate the ground distance in centimeters

12\text{ cm} \times 50,000 = 600,000\text{ cm}

A Representative Fraction of

1 : 50,000

means

1\text{ cm}

on the map corresponds to

50,000\text{ cm}

on the ground.

2

Convert centimeters to kilometers

600,000\text{ cm} \div 100,000 = 6\text{ km}

Since

1\text{ m} = 100\text{ cm}

and

1\text{ km} = 1,000\text{ m}

,

1\text{ km} = 100,000\text{ cm}

.

Key Concept

Distance calculation using Representative Fraction (R.F.) map scale

Question 12291Question →

During the dry season in Nigeria, a dust-laden wind blows from the Sahara Desert across the country, causing dry and hazy weather conditions. Which air mass is primarily responsible for bringing these conditions?

Tropical Maritime (mT) air mass

Continental Tropical (cT) air mass

Equatorial Maritime (eM) air mass

Polar Continental (cP) air mass

Show answer & explanation

Answer: Continental Tropical (cT) air mass

Answer

The Continental Tropical (cT) air mass is responsible for the dry and dusty Harmattan weather in Nigeria.

The Continental Tropical (cT) air mass originates over the dry Sahara Desert to the north. Driven by the North-East Trade Winds, it moves southward across Nigeria during the dry season, bringing dry, dusty, and hazy conditions known locally as the Harmattan.

Step-by-Step Solution

1

Identify the origin and characteristics of the specified weather phenomenon.

The dust-laden, dry wind blowing during the dry season is known as the Harmattan, coming from the dry Sahara Desert in the north.

Air masses acquire temperature and moisture characteristics from their source regions.

2

Match the weather characteristics to the correct air mass classification.

Continental Tropical (cT) air mass originates over land and desert regions in tropical latitudes, making it dry, warm, and dusty.

Maritime air masses bring moisture, whereas continental air masses bring dry air.

Key Concept

Air Masses of Nigeria and Harmattan Weather

Estimated Time:45s

Question 12292Question →

Town X is located at longitude $15^\circ\text{W}$ where the local solar time is recorded as $08:20\text{ AM}$ . At the exact same instant, a solar observatory at Town Y records a local solar time of $05:00\text{ PM}$ . What is the longitude of Town Y?

115^\circ\text{E}

115^\circ\text{W}

145^\circ\text{E}

145^\circ\text{W}

Show answer & explanation

Answer: $115^\circ\text{E}$

Answer

The longitude of Town Y is

115^\circ\text{E}

.

Because Town Y has a local solar time of

05:00\text{ PM}

compared to

08:20\text{ AM}

at Town X, Town Y is

8\text{ hours } 40\text{ minutes}

ahead. Converting this time difference to angular distance (

520\text{ minutes} \div 4 = 130^\circ

) shows Town Y is

130^\circ

east of

15^\circ\text{W}

. Traveling

15^\circ

east reaches the Greenwich Meridian (

0^\circ

), and the remaining

115^\circ

east places Town Y at

115^\circ\text{E}

.

Step-by-Step Solution

1

Calculate the time difference between Town X and Town Y

Time difference =

05:00\text{ PM} (17:00) - 08:20\text{ AM} = 8\text{ hours } 40\text{ minutes}

Determining the time span between the two locations provides the basis for calculating angular separation.

2

Convert the time difference into degrees of longitude

8\text{ hours } 40\text{ minutes} = 520\text{ minutes}

. Total angular distance =

520\text{ minutes} \div 4\text{ minutes/degree} = 130^\circ

Earth rotates

1^\circ

every 4 minutes (

15^\circ

per hour).

3

Determine direction and final longitude of Town Y

Since Town Y's time (

05:00\text{ PM}

) is ahead of Town X's time (

08:20\text{ AM}

), Town Y lies to the East of Town X. Moving

130^\circ

East from

15^\circ\text{W}

:

130^\circ - 15^\circ = 115^\circ\text{E}

Locations further east experience later local solar times. Crossing the

0^\circ

Prime Meridian shifts coordinates from West to East.

Key Concept

Calculating Longitude from Local Solar Time Differences Across Hemispheres

Question 12293Question →

An astronomical observatory located at longitude $64^\circ\text{E}$ records a cosmic ray pulse at $04:12\text{ PM}$ local solar time. Simultaneously, a ground monitoring station records the exact same event at $11:48\text{ AM}$ local solar time. What is the longitude of the ground monitoring station in degrees West ( $^\circ\text{W}$ )?

Show answer & explanation

Answer: 2

Answer

The longitude of the ground monitoring station is

2^\circ\text{W}

.

The time difference between

04:12\text{ PM}

(

16:12

) and

11:48\text{ AM}

(

11:48

) is

4\text{ hours and } 24\text{ minutes}

, which corresponds to an angular separation of

66^\circ

(

4 \times 15^\circ + 24/4^\circ

). Because the time at the ground station is earlier, it lies to the west of

64^\circ\text{E}

. Subtracting

66^\circ

from

64^\circ\text{E}

crosses the

0^\circ

Prime Meridian to reach

2^\circ\text{W}

.

Step-by-Step Solution

1

Calculate the difference in local solar time between the two stations.

Time difference =

16:12 - 11:48 = 4\text{ hours and } 24\text{ minutes}

.

Determining the time interval is the first step to finding angular separation.

2

Convert the total time difference into degrees of longitude.

(4 \times 15^\circ) + (24 \div 4^\circ) = 60^\circ + 6^\circ = 66^\circ

.

The Earth rotates

15^\circ

per hour (

1^\circ

every 4 minutes).

3

Determine the relative directional position of the ground station.

The ground station is

66^\circ

west of the observatory.

Earlier local solar time indicates a position further to the west.

4

Calculate the absolute longitude across the Prime Meridian.

66^\circ - 64^\circ\text{E} = 2^\circ\text{W}

.

Moving west from

64^\circ\text{E}

uses

64^\circ

to reach

0^\circ

, leaving

2^\circ

in the Western Hemisphere.

Key Concept

Calculating longitude position across hemispheres using local solar time differences.

Question 12294Question →

An international scientific symposium begins at $11:15\text{ AM}$ local solar time in City P, located at longitude $40^\circ\text{E}$ . At what local solar time does the symposium begin for a participant watching live from City Q, located at longitude $15^\circ\text{W}$ ?

07:35\text{ AM}

02:55\text{ PM}

09:35\text{ AM}

12:55\text{ PM}

Show answer & explanation

Answer: $07:35\text{ AM}$

Answer

07:35\text{ AM}

To find the time at City Q (

15^\circ\text{W}

) given the time at City P (

40^\circ\text{E}

), first calculate the total angular separation across the Prime Meridian:

40^\circ + 15^\circ = 55^\circ

. Multiplying by

4\text{ minutes per degree}

gives a total time difference of

220\text{ minutes}

, which equals

3\text{ hours } 40\text{ minutes}

. Because City Q is located to the west of City P, time must be subtracted:

11:15\text{ AM}

minus

3\text{ hours } 40\text{ minutes}

gives

07:35\text{ AM}

.

Step-by-Step Solution

1

Calculate the total longitudinal difference between City P (

40^\circ\text{E}

) and City Q (

15^\circ\text{W}

).

Longitudinal difference =

40^\circ + 15^\circ = 55^\circ

Since the two locations lie in different hemispheres (East and West), their longitudinal values must be added together to find total angular separation.

2

Convert the longitudinal difference into a time difference using the rate of

1^\circ = 4\text{ minutes}

.

Time difference =

55 \times 4\text{ minutes} = 220\text{ minutes} = 3\text{ hours } 40\text{ minutes}

The Earth rotates

360^\circ

in 24 hours, which corresponds to

15^\circ

per hour or

1^\circ

every 4 minutes.

3

Determine the local solar time at City Q by adjusting for directional orientation relative to City P.

11:15\text{ AM} - 3\text{ hours } 40\text{ minutes} = 07:35\text{ AM}

City Q is located to the west of City P, so its local time is behind (earlier than) City P.

Key Concept

Calculation of local solar time differences using longitudes across hemispheres

Estimated Time:1m 30s

Question 12295Question →

Field observations along a newly excavated mountain road cut in a humid tropical region reveal that intense seasonal rainfall caused a saturated, liquefied mantle of regolith to move rapidly downhill along a distinct shear plane. Which statement accurately classifies this process and distinguishes it from weathering?

It is a mass wasting event governed by gravitational shear stress, whereas weathering involves strictly in-situ rock disintegration without downslope material transport.

It is a chemical weathering process driven by hydrolysis, wherein rainwater directly transports dissolved minerals downslope.

It is physical exfoliation weathering, in which differential thermal expansion causes outer rock sheets to slide rapidly down steep gradients.

It is metamorphic recrystallization, in which extreme pore-water pressure alters clay minerals into slate, causing slope failure.

Show answer & explanation

Answer: It is a mass wasting event governed by gravitational shear stress, whereas weathering involves strictly in-situ rock disintegration without downslope material transport.

Answer

It is a mass wasting event governed by gravitational shear stress, whereas weathering involves strictly in-situ rock disintegration without downslope material transport.

The phenomenon described involves the rapid downhill movement of saturated soil and regolith down a slope under the primary force of gravity, which defines mass wasting (e.g., mudflow or debris slide). Weathering, by contrast, is strictly an in-situ breakdown of rock without mass displacement.

Step-by-Step Solution

1

Analyze the observed phenomenon described in the scenario.

The scenario describes bulk, rapid movement of saturated regolith down a slope along a shear surface following heavy rainfall.

Identifying whether the process involves material movement or in-place breakdown is necessary to categorize it.

2

Differentiate between weathering and mass wasting.

Weathering is strictly an in-situ process (disintegration or decomposition of rocks in place without movement), while mass wasting is the downslope transfer of rock material under the direct influence of gravity.

Understanding the fundamental distinction between transport mechanisms and in-situ alteration enables correct process identification.

3

Evaluate the options based on geographical definitions.

The movement of saturated regolith downhill under gravity is a mass wasting event (such as a mudflow or debris slide), confirming that the correct response properly identifies gravitational transport while contrasting it with stationary in-situ weathering.

Eliminating options that confuse chemical/physical weathering or metamorphic rock formation with mass wasting yields the correct answer.

Key Concept

Distinction between in-situ weathering and gravity-driven mass wasting processes

Question 12296Question →

A trader extracted a trial balance at 31st December 2025 showing physical stock at cost of $\text{N}64,000$ . Further inspection revealed that inventory costing $\text{N}14,000$ had suffered water damage and could only be sold for $\text{N}11,000$ after incurring $\text{N}2,000$ in reconditioning expenses. What is the correct figure for closing stock to be credited to the Trading Account?

\text{N}59,000

\text{N}61,000

\text{N}64,000

\text{N}57,000

Show answer & explanation

Answer: $\text{N}59,000$

Answer

\text{N}59,000

Under the prudence accounting convention, inventory is valued at the lower of cost and net realizable value (NRV). The cost of undamaged stock is

\text{N}50,000

(

\text{N}64,000 - \text{N}14,000

). The damaged stock has a cost of

\text{N}14,000

and an NRV of

\text{N}9,000

(selling price

\text{N}11,000

minus reconditioning costs

\text{N}2,000

). Taking the lower value for the damaged stock yields

\text{N}9,000

. Combining both gives

\text{N}50,000 + \text{N}9,000 = \text{N}59,000

.

Step-by-Step Solution

1

Calculate Net Realizable Value (NRV) of the damaged inventory

\text{NRV} = \text{Expected Selling Price} - \text{Reconditioning Costs} = \text{N}11,000 - \text{N}2,000 = \text{N}9,000

According to the prudence concept and inventory accounting rules, Net Realizable Value is defined as estimated selling price less expenses to complete or sell.

2

Determine cost of undamaged inventory

\text{Undamaged Stock Cost} = \text{Total Stock Cost} - \text{Damaged Stock Cost} = \text{N}64,000 - \text{N}14,000 = \text{N}50,000

Undamaged goods are valued at their cost price since net realizable value exceeds cost.

3

Calculate total valuation of closing inventory

\text{Total Closing Stock} = \text{Undamaged Stock} + \text{NRV of Damaged Stock} = \text{N}50,000 + \text{N}9,000 = \text{N}59,000

Closing inventory must be measured at the lower of cost and net realizable value for each item/category.

Key Concept

Valuation of Closing Inventory at the Lower of Cost and Net Realizable Value

Alternative Method

Calculate total stock cost (

\text{N}64,000

) and deduct the inventory write-down loss. Inventory Write-down =

\text{Cost} - \text{NRV} = \text{N}14,000 - (\text{N}11,000 - \text{N}2,000) = \text{N}5,000

. Closing stock valuation =

\text{N}64,000 - \text{N}5,000 = \text{N}59,000

.

Estimated Time:1m 30s

Question 12297Question →

Rocks are classified into three major groups based on their mode of formation. Which of the following features is a distinct characteristic of sedimentary rocks?

Stratification into layers and frequent inclusion of fossils

Interlocking crystalline structure resulting from deep thermal metamorphism

Down-slope mass movement of weathered debris driven purely by gravity

Foliated mineral banding formed by rapid cooling of molten volcanic lava

Show answer & explanation

Answer: Stratification into layers and frequent inclusion of fossils

Answer

Stratification into layers and frequent inclusion of fossils is the key defining feature of sedimentary rocks.

Sedimentary rocks are created by the deposition of organic and inorganic particles in successive strata (bedding planes). Because the process takes place at normal ambient temperatures on the surface, dead organisms buried in these layers can be preserved as fossils.

Step-by-Step Solution

1

Identify the rock formation process described.

Sedimentary rocks accumulate in layers (strata) through weathering, erosion, deposition, and lithification.

Understanding how sediments settle in water or land bodies explains their structural appearance.

2

Analyze unique characteristics resulting from this process.

Because formation occurs at low temperatures on the Earth's surface, organic material (plants and animals) can be buried and preserved as fossils between bedding planes.

Igneous rocks destroy fossils due to high molten temperatures, and metamorphic rocks deform or destroy fossils under extreme heat and pressure.

Key Concept

Characteristics of Sedimentary Rocks

Question 12298Question →

Match each natural resource on the left with its correct classification and environmental renewal characteristic on the right.

Click a left item, then click its matching right item

Show answer & explanation

Answer

Wind energy matches with inexhaustible renewable flow resource; Coal deposits match with exhaustible non-renewable resource; Soil fertility matches with conditionally renewable resource.

Wind energy is driven by atmospheric processes and is inexhaustible; coal is a finite fossil fuel created over millions of years; soil fertility is a biological-chemical asset that regenerates over time when managed responsibly.

Step-by-Step Solution

1

Determine the renewal capability of atmospheric energy sources.

Wind energy is inexhaustible and continuously available.

It is driven by ongoing solar radiation and atmospheric temperature dynamics.

2

Analyze the rate of formation of mineral fuels like coal.

Coal is an exhaustible non-renewable resource.

Geological accumulation takes millions of years, which far exceeds human generational timescales.

3

Evaluate the condition under which soil nutrient quality recovers.

Soil fertility is a conditionally renewable natural resource.

Natural organic cycling restores soil nutrients over time provided over-exploitation or severe erosion does not permanently degrade the land.

Key Concept

Differentiation between inexhaustible flow resources, non-renewable fossil fuels, and conditionally renewable environmental resources

Question 12299Question →

Match each topographic relief profile scenario to its corresponding calculated slope gradient expressed both as a ratio ( $1 \text{ in } N$ ) and as a percentage gradient.

Click a left item, then click its matching right item

Show answer & explanation

Answer

Trigonometric beacon to river confluence matches

1 \text{ in } 10

(

10\%

); Valley floor to plateau rim matches

1 \text{ in } 2.5

(

40\%

); Proposed railway track matches

1 \text{ in } 50

(

2\%

); Scarp face across 5 contour lines matches

1 \text{ in } 4

(

25\%

).

Each topographic scenario correctly pairs with its calculated gradient ratio and percentage by computing the exact Vertical Interval (difference in height) and Horizontal Equivalent (ground distance derived from map scale).

Step-by-Step Solution

1

Calculate the Vertical Interval (VI) for each scenario

Scenario 1:

450 - 150 = 300\text{ m}

. Scenario 2:

420 - 180 = 240\text{ m}

. Scenario 3:

220 - 100 = 120\text{ m}

. Scenario 4:

(5-1) \times 25 = 100\text{ m}

.

VI represents the difference in height between two points.

2

Calculate the Horizontal Equivalent (HE) in meters for each scenario

Scenario 1:

6\text{ cm} \times 500\text{ m/cm} = 3,000\text{ m}

. Scenario 2:

2.4\text{ cm} \times 250\text{ m/cm} = 600\text{ m}

. Scenario 3:

12\text{ cm} \times 500\text{ m/cm} = 6,000\text{ m}

. Scenario 4:

0.8\text{ cm} \times 500\text{ m/cm} = 400\text{ m}

.

Convert map distance to ground distance using the representative fraction scale.

3

Compute the slope gradient ratio (VI / HE) and express as 1 in N and percentage

Scenario 1:

300 / 3000 = 1/10 = 1 \text{ in } 10

(

10\%

). Scenario 2:

240 / 600 = 1/2.5 = 1 \text{ in } 2.5

(

40\%

). Scenario 3:

120 / 6000 = 1/50 = 1 \text{ in } 50

(

2\%

). Scenario 4:

100 / 400 = 1/4 = 1 \text{ in } 4

(

25\%

).

Gradient is calculated as VI / HE, yielding both ratio 1 in N and percentage slope (VI/HE * 100%).

Key Concept

Slope and Gradient Calculation

Question 12300Question →

Match each African political entity in Column A with its corresponding unique political-geographical boundary or territorial characteristic in Column B.

Click a left item, then click its matching right item

Show answer & explanation

Answer

Lesotho matches with being an enclave completely surrounded by South Africa; Cabinda matches with being an angolan exclave separated by DRC territory; Equatorial Guinea matches with having its capital Malabo on Bioko Island separate from mainland Río Muni; The Gambia matches with being a riverine nation almost entirely surrounded by Senegal.

Each matching pair accurately reflects established geopolitical terminology and territorial features in African geography: Lesotho is an enclave within South Africa; Cabinda is an Angolan exclave across DRC territory; Equatorial Guinea places its capital on Bioko Island off mainland Río Muni; and The Gambia is virtually surrounded by Senegal along the Gambia River.

Step-by-Step Solution

1

Analyze the geographical position of Lesotho relative to its surrounding borders.

Lesotho is entirely surrounded by South Africa, establishing it as an enclave state.

An enclave is a territory completely surrounded by another single foreign state.

2

Examine the political division of Angola's northern territory of Cabinda.

Cabinda is separated from mainland Angola by the Democratic Republic of the Congo's narrow coastal corridor along the Congo River.

This spatial separation defines Cabinda as a political exclave.

3

Identify the multi-part territory of Equatorial Guinea.

Equatorial Guinea consists of mainland Río Muni and offshore islands, with its capital Malabo located on Bioko Island.

This creates a unique arrangement where the national capital is geographically isolated from the country's mainland region.

4

Evaluate the political geography of West Africa regarding The Gambia.

The Gambia forms a narrow ribbon state centered on the Gambia River and is surrounded on three sides by Senegal.

Its boundary shape makes it a semi-enclave within Senegal.

Key Concept

Political-Geographical Terminology and Territorial Patterns in Africa

Estimated Time:2m 0s

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