ELECTRODYNAMICS
FULL PHYSICAL SCIENCES STUDY GUIDE
Definitions • visual methods • worked examples • exam practice
PRIVATE TUTORING • KAYLA THRING
, Contents
1. Magnetic fields & direction rules 3
2. Fields around loops & solenoids 4
3. Force on a current-carrying conductor 5
4. Direct-current motors 6
5. Magnetic flux & flux linkage 7
6. Electromagnetic induction 8
7. Faraday's law & Lenz's law 9
8. Flux-time & emf-time graphs 10
9. Alternating-current generators 11
10. Generator output 12
11. Transformers 13
12. Ideal transformer calculations 14
13. AC & the national grid 15
14. Diodes & rectification 16
15. Problem-solving checklist 17
16. Practice questions 18
17. Final formula & rule sheet 20
ELECTRODYNAMICS • KAYLA THRING STUDY NOTES 2
, 1. Magnetic fields & direction rules
CORE CONCEPT • FIELD PATTERNS + RIGHT-HAND GRIP RULE
PRESCRIBED FACT
A magnetic field exists around a permanent magnet or a current-carrying conductor.
A magnetic field is the region in which a magnet, magnetic material or moving charge experiences a magnetic force.
Field-line arrows show direction, while closer spacing represents a stronger field.
1.1 Permanent magnet
Outside a bar magnet, field lines point from north to south. Inside the magnet they return from south to north, forming
closed loops. Field lines never cross.
1.2 Straight current-carrying conductor
Use the right-hand grip rule: point your right thumb in the direction of conventional current. Your curled fingers show
the direction of the circular magnetic field lines.
DIRECTION SYMBOLS
• means current coming out of the page. × means current going into the page.
EXAM TIP
When asked to draw a magnetic field, include arrowheads. A field pattern without direction is incomplete.
ELECTRODYNAMICS • KAYLA THRING STUDY NOTES 3
FULL PHYSICAL SCIENCES STUDY GUIDE
Definitions • visual methods • worked examples • exam practice
PRIVATE TUTORING • KAYLA THRING
, Contents
1. Magnetic fields & direction rules 3
2. Fields around loops & solenoids 4
3. Force on a current-carrying conductor 5
4. Direct-current motors 6
5. Magnetic flux & flux linkage 7
6. Electromagnetic induction 8
7. Faraday's law & Lenz's law 9
8. Flux-time & emf-time graphs 10
9. Alternating-current generators 11
10. Generator output 12
11. Transformers 13
12. Ideal transformer calculations 14
13. AC & the national grid 15
14. Diodes & rectification 16
15. Problem-solving checklist 17
16. Practice questions 18
17. Final formula & rule sheet 20
ELECTRODYNAMICS • KAYLA THRING STUDY NOTES 2
, 1. Magnetic fields & direction rules
CORE CONCEPT • FIELD PATTERNS + RIGHT-HAND GRIP RULE
PRESCRIBED FACT
A magnetic field exists around a permanent magnet or a current-carrying conductor.
A magnetic field is the region in which a magnet, magnetic material or moving charge experiences a magnetic force.
Field-line arrows show direction, while closer spacing represents a stronger field.
1.1 Permanent magnet
Outside a bar magnet, field lines point from north to south. Inside the magnet they return from south to north, forming
closed loops. Field lines never cross.
1.2 Straight current-carrying conductor
Use the right-hand grip rule: point your right thumb in the direction of conventional current. Your curled fingers show
the direction of the circular magnetic field lines.
DIRECTION SYMBOLS
• means current coming out of the page. × means current going into the page.
EXAM TIP
When asked to draw a magnetic field, include arrowheads. A field pattern without direction is incomplete.
ELECTRODYNAMICS • KAYLA THRING STUDY NOTES 3
