中文（繁體）
中文（简体）
English
Primary General Studies: Hong Kong Weather Warnings and Natural Hazards (Paper 4 (error clinic))
Primary General Studies: Hong Kong Weather Warnings and Natural Hazards (Paper 4 (error clinic))
Paper four drills the ten commonest slips: the order of signals, the three rainfall thresholds, judging the level from rainfall, wind speed gaps, accumulated rainfall, distance and speed, temperature gaps, and safe behaviour in a rainstorm.
Direct answers After each answer ask whether the question is about a threshold, a calculation or a safety step, then check the units.
01 Paper details (check answers afterwards)
| Item | Detail |
|---|---|
| Questions | 10 |
| Suggested time | 20 |
| Difficulty mix | Foundation 3 · Intermediate 3 · Challenge 3 · Error redo 1 |
| Chapter | Chapter: Primary General Studies: Hong Kong Weather Warnings and Natural Hazards |
| Level | parts of a closed circuit, conductors against insulators, series against parallel, adding up battery voltage, and electrical safety |
02 Questions (10 items)
- FoundationPut the tropical cyclone signals in order from lowest to highest.
- FoundationWhat is the hourly rainfall threshold for the black rainstorm warning?
- FoundationWhat is the hourly rainfall threshold for the red rainstorm warning?
- IntermediateSixty millimetres of rain in an hour belongs to which warning?
- IntermediateHow many kilometres per hour apart are signal 8 and signal 10?
- IntermediateRain falls at thirty-five millimetres per hour for four hours. What is the total?
- ChallengeA typhoon is eight hundred kilometres away and moves at forty kilometres per hour. How long until closest approach?
- ChallengeThe hot warning is thirty-three degrees and the cold warning twelve. How far apart are they?
- ChallengeNinety millimetres falls in three hours. What is the hourly average?
- Error redoA classmate says swimming outdoors during black rain is fine. What is wrong?
03 Answers and one-line notes
| # | Answer | One-line note |
|---|---|---|
| 1 | Signal 1, 3, 8, 9 and 10. | Signal 1 is the lowest and signal 10 the highest; the bigger number means stronger wind. |
| 2 | Seventy millimetres. | The three thresholds are thirty, fifty and seventy millimetres. |
| 3 | Fifty millimetres. | Red sits above amber and below black. |
| 4 | The red rainstorm warning. | Sixty is above fifty but below seventy, so it is red. |
| 5 | Fifty-five kilometres per hour apart. | One hundred and eighteen minus sixty-three is fifty-five. |
| 6 | One hundred and forty millimetres. | Thirty-five times four is one hundred and forty. |
| 7 | Twenty hours. | Eight hundred divided by forty is twenty. |
| 8 | Twenty-one degrees apart. | Thirty-three minus twelve is twenty-one. |
| 9 | Thirty millimetres per hour. | Ninety divided by three is thirty. |
| 10 | It ignores danger; during a rainstorm stay somewhere safe and away from rivers and the sea. | Heavy rain raises water levels fast and can trigger landslides, so water activities are very dangerous. |
04 What to do after marking
- After marking, redo only the wrong items and write down which step went wrong (formula, unit, or misread number).
- Repeat the same item two days later; move to the next paper only when both attempts are correct.
- Parents only need the answer and note columns; there is no need to explain every item.
With all four done, go back to the chapter page and revise the three parts of a closed circuit plus three safety habits.Tutor Registration →
Questions and answers are written originally by the TutorZone team and are not taken from any school, publisher or examination authority paper. Every value is checked by computer.