The questions are on the electromagnet test. Take it under real conditions before reading the mark scheme.
Quick answer: A magnet has a north and a south pole: like poles repel and unlike poles attract. This mark scheme gives the model answers and the marks for the 8 questions of the grade 8 science test on electromagnet, from poles to cutting a magnet, with the equivalent answers to accept.
Also, the model answers show the expected scientific words. Marks are awarded for stating a correct fact and for giving a reason. In addition, compare each answer with your own and check which mark points you missed.
Level: Grade 8 science (Year 9 · Class 8) · Curriculum: MS-PS2-3, MS-PS2-5
Question 2 Field lines (3 marks)
- From the north pole to the south pole.
- Point X. It is beside a pole, where the field lines are closest together; Z is far from the lines, so its field is weakest.
Marking: Part a: 1 mark. Part b: 1 mark for X, 1 mark for the reason about line spacing.
Question 3 Which are attracted? (2 marks)
- Also, the steel spoon and the nickel key.
- Copper is not a magnetic material, so it is not attracted to a magnet.
Marking: 1 mark each part.
Question 4 The compass (3 marks)
- It can spin freely and is attracted and repelled by other magnets, as only a magnet can do.
- In addition, the Earth has a magnetic field like a giant bar magnet, and the needle lines up with it.
- Moreover, the needle lines up with the field of the nearby magnet, which is stronger than the Earth’s field there.
Marking: 1 mark per part.
Question 5 Stronger electromagnet (3 marks)
Add more turns of wire; increase the current (more cells or a bigger supply); put an iron core inside the coil.Marking: 1 mark for each correct change.
Question 6 Clips and current (3 marks)
- The clips lifted are proportional to the current: they double when the current doubles.
- 1.6 A is 4 × 0.4 A, so 4 × 5 = 20 clips.
- Increase = 15 − 5 = 10; 10 ÷ 5 × 100 = 200 %.
Marking: 1 mark per part.
Question 7 Breaker’s yard (2 marks)
Also, it can be switched off to release the load, and its strength can be changed for light or heavy loads.Marking: 1 mark for each reason.
Question 8 Cutting a magnet (2 marks)
Each piece has a north pole and a south pole. Each part of the magnet is itself a small magnet, so poles always come in pairs.Marking: 1 mark for N and S on each piece, 1 mark for the explanation.
