Grade 8 : Social Science (Exploring Society) - Natural Resources (Set 1) | Concept of Maths

Question 1

1. If Earth has a total water volume of $V$, and only $2.7\%$ is fresh water, of which $70\%$ is trapped in ice sheets/glaciers, what percentage of $V$ is actually accessible as liquid fresh water for human use?

A) $2.7\%$

B) $1.89\%$

C) Less than $1\%$

D) $0.03\%$

Answer

Correct Answer: C

Solution: Total Fresh Water $= 2.7\% \text{ of } V$. Trapped water $= 70\% \text{ of } 2.7\% = 0.70 \times 2.7 = 1.89\%$. Accessible water $= 2.7\% - 1.89\% = 0.81\%$.  Since $0.81\% < 1\%$, the answer is C.

Question 2

2. A resource is classified as "Ubiquitous" if its spatial distribution function $f(x,y)$ is constant across the globe. Which of the following is a ubiquitous resource?

A) Copper Ore

B) The Air we breathe

C) Petroleum Reservoirs

D) Uranium Deposits

Answer

Correct Answer: B

Solution: Ubiquitous resources are found everywhere (like air/sunlight). Localized resources (like copper or iron) are found only in specific geographic locations.

Question 3

3. Sustainable development requires that the rate of resource consumption $R_c$ and the rate of resource regeneration $R_r$ satisfy which inequality to maintain ecological balance?

A) $R_c \le R_r$

B) $R_c > R_r$

C) $R_c \times R_r = 0$

D) $R_c = R_r^2$

Answer

Correct Answer: A

Question 4

4. In the context of biotic resources, if a population of trees grows at a rate of $P(t) = P_0 e^{rt}$, which factor primarily categorizes them as renewable?

A) Their inorganic origin

B) Their fixed stock $(S)$

C) Their high market value

D) Their ability to reproduce and regenerate

Answer

Correct Answer: D

Solution: Renewable resources are those which get renewed or replenished quickly. Biotic resources like plants and animals can reproduce ($r > 0$), making them renewable.

Question 5

5. Soil formation is a slow process where it takes roughly $T = 100$ years to form just $1\text{ cm}$ of soil. If a region loses $5\text{ cm}$ of topsoil due to erosion in $1$ year, what is the net deficit in years of natural production?

A) $5$ years

B) $100$ years

C) $500$ years

D) $20$ years

Answer

Correct Answer: C

Solution: Time to form $1 \text{ cm} = 100 \text{ years}$. Time to form $5 \text{ cm} = 5 \times 100 = 500 \text{ years}$. Loss of $5 \text{ cm}$ in $1 \text{ year}$ negates $500 \text{ years}$ of natural work.

Question 6

6. Which of the following is considered a "Human-made Resource"?

A) Iron ore found in the crust

B) Technology used to extract iron

C) Tropical rainforests

D) Natural gas deposits

Answer

Correct Answer: B

Solution: Natural substances become resources only when their original form has been changed. Technology, bridges, and machinery are Human-made resources.

Question 7

7. Resource value is not always economic. If $V_e$ is economic value and $V_a$ is aesthetic value, a beautiful landscape primarily possesses:

A) Only $V_e$

B) $V_e > V_a$

C) Neither $V_e$ nor $V_a$

D) High $V_a$

Answer

Correct Answer: D

Solution: Some resources have economic value (metals), while others like a beautiful landscape have aesthetic value. Both are important for human needs.

Question 8

8. The "Ecological Footprint" measures the demand on Earth's ecosystems. If a country's footprint $F$ exceeds its biocapacity $B$, the country is in:

A) Ecological Deficit

B) Ecological Surplus

C) Sustainable Equilibrium

D) Resource Abundance

Answer

Correct Answer: A

Solution: If $F > B$, the population is consuming resources faster than the ecosystem can provide, resulting in a deficit.

Question 9

9. Which conservation method involves planting rows of trees to check wind movement, especially in coastal and dry regions?

A) Mulching

B) Shelter belts

C) Contour barriers

D) Intercropping

Answer

Correct Answer: B

Solution: Shelter belts are rows of trees planted to reduce wind speed and prevent soil erosion in open areas.

Question 10

10. CITES (the Convention on International Trade in Endangered Species) aims to ensure that international trade in specimens of wild animals and plants does not threaten their survival. This is an example of:

A) Local resource exploitation

B) Economic trade maximization

C) Global conservation effort

D) Agricultural expansion

Answer

Correct Answer: C

Solution: CITES is an international agreement between governments to protect endangered species from over-exploitation through international trade.

Grade 8 : Social Science (Exploring Society) - Natural Resources (Set 1) | Concept of Maths