中文（繁體）
中文（简体）
English
P4 General Studies: Magnetism and the Compass (Paper 3 (challenge))
Tutor Prep Guide · the digestive system and the food pyramid, enzymes and bile, energy and nutrient calculations, and balanced eating habits
P4 General Studies: Magnetism and the Compass (Paper 3 (challenge))
Paper three covers domains, electromagnets and proportional strength, with three before-and-after sums.
Direct answers For before-and-after questions always use the original value as the denominator.
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: P4 General Studies: Magnetism and the Compass |
| Level | parts of a closed circuit, conductors against insulators, series against parallel, adding up battery voltage, and electrical safety |
02 Questions (10 items)
- FoundationWhat small regions make up a magnetic material?
- FoundationWhy does a magnet weaken after heating or hard knocking?
- FoundationWhat happens to an electromagnet when the current is switched off?
- IntermediateWith the same current, the coil turns are doubled. What happens to the electromagnet force?
- IntermediateA 3-turn coil lifts 6 nails. With the same current and 9 turns, how many nails are expected?
- IntermediateIn an experiment the current rises from 2 A to 4 A and the force rises from 8 to 16 units. What is the increase in percentage points?
- ChallengeAfter heating to 80 °C a magnet falls from 12 to 9 units. What is the decrease in percentage points?
- ChallengeA magnet lifts five eighths of the 48 nails in a box. How many are left in the box?
- ChallengeA needle swings from 15 degrees to 45 degrees. Through what angle has it turned?
- Error redoError clinic: a compass always points to true north. True?
03 Answers and one-line notes
| # | Answer | One-line note |
|---|---|---|
| 1 | Magnetic domains. | When the domains line up the material is magnetic; when they point at random their effects cancel. |
| 2 | The arrangement of magnetic domains is disturbed. | Heat or vibration scatters the domains, so the overall magnetism drops. |
| 3 | It loses its magnetism. | A current-carrying coil makes a field, so switching off removes it and an electromagnet can be turned on and off. |
| 4 | It increases. | More turns and more current give a stronger field, and an iron core strengthens it further. |
| 5 | 18 nails. | Two nails per turn gives 18 for 9 turns, so turns and lift are proportional. |
| 6 | 100.0 percentage points. | The force gains 8 units; 8 divided by the original 8 times 100 gives 100.0 percentage points. |
| 7 | 25.0 percentage points. | It loses 3 units; 3 divided by 12 times 100 gives 25.0 percentage points. |
| 8 | 18 nails left. | Thirty nails are lifted, and 48 minus 30 leaves 18. |
| 9 | 30 degrees. | Subtract 15 from 45 to get 30 degrees; the swing shows a change in field direction. |
| 10 | No. | The magnetic pole is offset from the geographic pole, and nearby iron or magnets deflect the needle. |
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.
Paper four clears the conductor, insulator and battery direction misconceptions.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.