Secondary 4 Geography Physical Geography Quiz

Secondary 4 Geography Quiz - Physical Geography (Answer Key)

Total Marks: 40
Topic: Physical Geography (Climate & Tectonics)

Section A: Short Structured Questions (1–8)

1. [1] One cause: Burning of fossil fuels releases CO₂ which traps heat.
Teaching note: Greenhouse effect is when gases (CO₂, methane) absorb outgoing infrared radiation. Fossil fuel combustion is a key anthropogenic source.

2. [1] Adiabatic cooling (or uplift and cooling).
Teaching note: As air rises, pressure drops, it expands and cools without heat loss; condensation occurs when dew point reached.

3. [1] The focus is the point inside the Earth where the earthquake rupture starts.
Teaching note: Contrast with epicentre (point on surface above focus).

4. [1] Primary effect: Lava flow / ash fall / pyroclastic flow (any one).
Teaching note: Primary = direct physical outbreak; secondary = e.g., famine, disease.

5. [1] Constructive (or divergent) boundary.
Teaching note: Plates move apart; new crust forms (e.g., Mid-Atlantic Ridge).

6. [1] Deforestation / burning coal / driving petrol cars (any one).
Teaching note: Removes sinks or adds CO₂.

7. [1] Solar power / wind power / hydroelectric (any one).
Teaching note: Renewable = naturally replenished, low carbon.

8. [1] Epicentral distance.
Teaching note: Derived from time lag between P and S waves.

Section B: Data and Diagram Interpretation (9–14)

9. [3]
(a) [2] Temperature high year-round (27–28°C), variation <2°C.
(b) [1] Rainfall high (1900mm total), lower in mid-year (Jul 80mm), peaks Apr & Oct.
Marking: 2 marks for quantified temp description, 1 for rainfall pattern.
Teaching: Equatorial climate shows low annual temp range; convectional rain peaks at equinoxes.

10. [2] Characteristics: (1) High wave height (~3m); (2) Backwash stronger than swash; (3) Frequent (12/min). Any two = 2 marks.
Teaching: Destructive waves erode coast, steep profile.

11. [3] Explanation: Waves attack headland base (hydraulic action) → cracks widen → arch forms when crack penetrates. 1 mark location, 2 marks process.
Teaching: Limestone weak at joints; wave concentration exploits lines of weakness.

12. [2] Mean = (5.2+6.1+4.8+6.5+5.9)/5 = 28.5/5 = 5.7.
Working: Sum = 28.5, ÷5 = 5.7 Richter.
Marking: 1 for sum, 1 for division/answer.

13. [2] Convergent (destructive) boundary; landform: volcano / trench.
Teaching: Subduction melts plate → magma rises → volcano.

14. [2] Temperate (e.g., temperate continental); reason: large annual range (2→18°C = 16°C).
Teaching: Equatorial <5°C range; temperate shows seasonality.

Section C: Extended Structured Response (15–20)

15. [4] Convectional rainfall: (1) Intense solar heating of ground [1]; (2) Warm air rises, expands, cools adiabatically [1]; (3) At condensation level clouds form [1]; (4) Heavy afternoon convectional storms common [1].
Teaching: Equatorial latitudes receive high insolation; unstable air.

16. [4] Factors: (1) Greenhouse gas emissions from fossil fuels [2: example + link]; (2) Deforestation reduces CO₂ sink [2].
Marking descriptors: 2 marks each with mechanism stated.

17. [4] Process: (1) Hydraulic action compresses air in cracks, breaking rock [2]; (2) Abrasion by load scrapes cliff, enlarges arch [1]; (3) Continued erosion isolates stack [1].
Teaching: Stack = remnant after arch collapse.

18. [4] Named volcano (e.g., Mt Pinatubo 1991): Primary – ash, lava, pyroclastic flows [2]; Secondary – lahars, crop loss, climate cooling [2].
Marking: 2+2 for correct classification with example.

19. [4] Developed: better building codes → fewer deaths [2]; Developing: poor infrastructure → more casualties, slower aid [2].
Teaching: Capacity links to GDP, governance.

20. [4] Impacts: (1) Sea level rise → flooding of low islands [1+1]; (2) Stronger storms → erosion [1]; (3) Saltwater intrusion → agriculture loss [1].
Marking: 4 points with SEA context (e.g., Jakarta, Mekong Delta).