中文（繁體）
中文（简体）
English
P3 General Studies: Light and Shadows (Paper 2 (intermediate))
Tutor Prep Guide · straight-line light, shadow direction and length, reflection angles and the normal, sundials and pinhole images
P3 General Studies: Light and Shadows (Paper 2 (intermediate))
Paper two adds the normal, angle of reflection calculations, ratios and percentages, with shadow shrinkage as the percentage context.
Direct answers Draw the normal first, then write that the angle of reflection equals the angle of incidence before doubling for the angle between rays.
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: P3 General Studies: Light and Shadows |
| Level | parts of a closed circuit, conductors against insulators, series against parallel, adding up battery voltage, and electrical safety |
02 Questions (10 items)
- FoundationIn mirror reflection, what is the angle between the incoming ray and the normal called?
- FoundationHow many degrees is the normal to the mirror surface?
- FoundationIf the angle of incidence is 30 degrees, what is the angle of reflection?
- IntermediateWith an angle of incidence of 30 degrees, what is the angle between the incoming and reflected rays?
- IntermediateWith an angle of incidence of 40 degrees, what is the angle between the two rays?
- IntermediateA 1.5 m object casts a 2 m shadow. What is the ratio of height to shadow length?
- ChallengeFive of eight torches send light straight through a small hole. What percentage is that?
- ChallengeA shadow shrinks from 1.2 m to 0.6 m. By what percentage did it shrink?
- ChallengeHow far does one 45 degree mirror in a periscope turn a light ray?
- Error redoA classmate draws the reflected ray 40 degrees from the mirror surface. What is wrong?
03 Answers and one-line notes
| # | Answer | One-line note |
|---|---|---|
| 1 | The angle of incidence | The angle between the incoming ray and the normal is the angle of incidence. |
| 2 | 90 degrees, the normal is perpendicular to the mirror | The normal is drawn perpendicular to the mirror, so it makes 90 degrees with the surface. |
| 3 | 30 degrees | The angle of reflection always equals the angle of incidence. |
| 4 | 60 degrees | Both angles are measured from the normal, so 30 plus 30 gives 60 degrees. |
| 5 | 80 degrees | Forty plus forty gives 80 degrees. |
| 6 | 0.75 | One point five divided by two equals 0.75. |
| 7 | 62.5 Percentage points | Five divided by eight times one hundred gives 62.5 percentage points. |
| 8 | 50.0 Percentage points | It shrank by 0.6 m, and 0.6 divided by 1.2 times one hundred gives 50.0 percentage points. |
| 9 | 90 degrees | The ray meets the mirror at 45 degrees and leaves at 45 degrees, a total turn of 90 degrees. |
| 10 | The angle must be measured from the normal, not from the surface | Both angles are measured from the normal, so measuring from the surface turns 50 degrees into 40. |
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.
Then try paper three, using voltage and current to work out power and resistance.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.