Correct Answer: D. 6⁵/₁₂cm²

Explanation

Area of sector = \(\frac{\theta}{360°} \times \pi r^2\)

= \(\frac{60}{360} \times \frac{22}{7} \times 3.5 \times 3.5\)

= \(\frac{77}{12}\)

= \(6\frac{5}{12}\) cm\(^2\)

Correct Answer: C. a competitive market structure

Explanation

(a) -Efficient Movement of Goods: Rail transportation allows for the efficient movement of goods across long distances. It can accommodate large quantities of cargo, making it an ideal mode of transport for industries such as agriculture, mining, and manufacturing in tropical Africa. This efficiency helps stimulate trade and economic growth.

-Reduced Congestion: Compared to road transportation, rail systems help alleviate congestion on major highways. By diverting a significant portion of freight traffic to rail, the congestion on roads is reduced, resulting in smoother traffic flow, decreased travel times, and improved road safety.

-Lower Environmental Impact: Rail transportation is more environmentally friendly compared to road transport. Trains emit less carbon dioxide per ton of freight compared to trucks, reducing greenhouse gas emissions and air pollution. This advantage is crucial for tropical Africa's sustainability efforts and can contribute to mitigating climate change impacts.

-Enhanced Connectivity: Rail networks provide enhanced connectivity by linking remote areas and cities, facilitating economic integration and regional development. They enable access to markets, resources, and employment opportunities, boosting trade, tourism, and economic activities across tropical Africa.

-Increased Accessibility: Rail systems provide reliable and accessible transportation for both passengers and goods. They offer a cost-effective means of travel, making it easier for people to commute between cities and towns, visit tourist destinations, and access essential services such as healthcare and education. This accessibility helps bridge the gap between rural and urban areas.

-Job Creation: Developing rail infrastructure in tropical Africa generates employment opportunities in various sectors. From construction and maintenance to operation and management, rail projects create jobs for engineers, technicians, drivers, station staff, and support personnel. This job creation contributes to economic development and poverty reduction.

-Long-term Cost Savings: While initial investments in rail infrastructure may be significant, in the long run, rail transport can be cost-effective. Railways have lower operating costs compared to road transport due to lower fuel consumption, reduced vehicle maintenance, and decreased road damage. These cost savings can be beneficial for both businesses and governments.

(b) -Insufficient Infrastructure: Many countries in tropical Africa have outdated and inadequate rail infrastructure. The existing rail networks often suffer from poor maintenance, outdated technology, and insufficient capacity. This results in slower speeds, frequent breakdowns, and limited connectivity, hindering the smooth movement of goods and passengers.

-Funding Constraints: Lack of adequate funding is a major challenge for rail projects in tropical Africa. Limited financial resources lead to delays in infrastructure upgrades, repairs, and expansion, hampering the overall efficiency of rail transportation.

-Inadequate Maintenance: Due to financial constraints and lack of technical expertise, rail infrastructure in tropical Africa often suffers from inadequate maintenance. This results in deteriorating tracks, bridges, and signaling systems, leading to frequent disruptions, delays, and safety concerns.

-Lack of Interconnectivity: Many rail networks in tropical Africa suffer from a lack of interconnectivity, limiting their reach and effectiveness. Incomplete or fragmented rail systems make it challenging to transport goods seamlessly across different regions, hindering economic integration and trade.

-Inefficient Operations: Inefficient operations and management practices contribute to the problems facing rail transportation in tropical Africa. Factors such as outdated technology, inadequate training of staff, and suboptimal scheduling and coordination lead to delays, inefficiencies, and reduced service quality.

-Insecurity: Rail transportation in tropical Africa often faces security challenges such as vandalism, theft, and sabotage. These incidents not only disrupt operations but also pose risks to the safety of passengers and cargo.

(c) -Insufficient Infrastructure: Increased investment in rail infrastructure by seeking partnerships with international organizations, private sector entities, and foreign investors can provide the necessary funding for infrastructure upgrades, expansion, and modernization, thereby improving the capacity and quality of rail networks.

-Funding Constraints: Governments can offer incentives and create a conducive business environment to encourage private sector participation.

-Inadequate Maintenance: Government should establish a dedicated maintenance fund for rail infrastructure, ensuring a regular and sufficient budget allocation for maintenance activities and a

Correct Answer: B. 624 C.E

Explanation

(a) Causes of desert encroachment;

(i) Prolonged drought

(ii) Over grazing

(iii) Deforestation or uncontrolled tree felling

(iv) Bush burning

(b) Areas liable:

(I) Desert margins e.g sahel regions

(ii) Sudan Savannah, e.g Sokoto, Maiducuri

(iii) Extreme northern part of Nigeria

(c) Effects;

(i) Loss of vegetation

(ii) Changes in climate of the areas

(iii) Loss of agricultural land

(iv) Loss of animals and humans by death

(d) Methods of preservation:

(i) Afforestation i.e planting of trees

(ii) Controlled grazing

(iii) Controlled tree felling/deforestation

(iv) Controlled or legislation against bush burning

Correct Answer: A. personification and simile

Correct Answer: B. legislative acts and statutes

Explanation

Public corporations and parastatals are typically established by legislative acts and statutes. These are government-owned entities created to undertake commercial activities on behalf of the government.

Correct Answer: B. The electric potential energy of a negatively charged particle increases when it moves to a point of lower potential .

Explanation

The potential energy for a positive charge increases when it moves against an electric field. And decreases when it moves with the electric field; The opposite is true for a negative charge. Unless the unit charge crosses a changing magnetic field, its potential at any given point does not depend on the path taken.

Correct Answer: B) at zero price, quantity supplied exceeds quantity demanded

Explanation

This question is asking about a free good and which situation represents a free good. A free good is a good that is available in abundance and has no opportunity cost. In other words, it is a good that can be obtained without paying a price.

Option A states that when more is demanded than supplied at zero price, we have a free good. This is incorrect because if there is more demand than supply, it means the good is scarce and not freely available.

Option C states that at equilibrium price, quantity supply is equal to quantity demanded. This does not represent a free good because there is still a price attached to it.

Option D states that any quantity can be obtained when the price is low. This does not represent a free good because there is still a price attached to it.

Option B states that at zero price, quantity supplied exceeds quantity demanded. This represents a free good because it is available in abundance and there is no price attached to it. Examples of free goods include air, sunlight, and water from natural sources.

In summary, the correct answer is Option B, which represents a free good. To learn more about this, please read the relevant sections of the recommended textbooks.

Correct Answer: A. 14