3 equations, all Higher tier. Each page has 10 real-life ramped questions with full FIFA solutions. Every equation is given on the equation sheet in the exam.
Key: C+S = Combined and Separate | S only = Separate Physics only | HT = Higher tier only
- Motor effect: F = BIl (C+S, HT)
- Transformers: Vₚ/Vₛ = nₚ/nₛ (S only, HT)
- Transformers: VₚIₚ = VₛIₛ (S only, HT)
Key definitions
Write your answer on paper first, then tap Show answer. Learn the key words – definition questions are quick marks in the exam.
1. What is a magnetic field? (C+S)
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The region around a magnet where a force acts on another magnet or on a magnetic material.
2. Name four magnetic materials. (C+S)
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Iron, steel, cobalt and nickel.
3. What is the difference between a permanent magnet and an induced magnet? (C+S)
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A permanent magnet produces its own magnetic field. An induced magnet becomes a magnet only when it is placed in a magnetic field, and quickly loses most or all of its magnetism when removed. Induced magnetism always causes a force of attraction.
4. Which way do magnetic field lines point, and where is the field strongest? (C+S)
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Field lines go from the north pole to the south pole. The field is strongest at the poles, where the lines are closest together.
5. What is a solenoid? Describe the magnetic field inside it. (C+S)
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A coil of wire. When a current flows through it, the magnetic field inside is strong and uniform. Outside, the field is like that of a bar magnet.
6. What is an electromagnet? (C+S)
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A solenoid with an iron core. The iron core increases the strength of the magnetic field, and the magnetism can be switched on and off with the current.
7. What is the motor effect? (C+S, HT)
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When a conductor carrying a current is placed in a magnetic field, the magnet and the conductor exert a force on each other.
8. What does each finger represent in Fleming’s left-hand rule? (C+S, HT)
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Thumb: direction of the force (motion). First finger: direction of the magnetic field (N to S). Second finger: direction of the current.
9. What is magnetic flux density? (C+S, HT)
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A measure of the strength of a magnetic field. Unit: tesla (T).
10. What is the generator effect? (S only, HT)
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A potential difference is induced across a conductor when it moves relative to a magnetic field, or when there is a change in the magnetic field around it. If the conductor is part of a complete circuit, a current is induced.
11. How does a transformer work? (S only, HT)
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An alternating current in the primary coil produces a changing magnetic field in the iron core. This changing field passes through the secondary coil and induces an alternating potential difference across it.
12. What is the difference between a step-up and a step-down transformer? (S only, HT)
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A step-up transformer has more turns on the secondary coil than the primary, so it increases the p.d. A step-down transformer has fewer turns on the secondary coil, so it decreases the p.d.
