Cambridge International AS & A Level · 20 · structured
Produce all three current-field sketches
Sketch fields of a wire, a flat circular coil and a solenoid · Original GioPhysics question with a detailed, mark-by-mark answer guide.
- Demand
- demanding
- Marks
- 8
- Topics
- 1
- Answer
- Complete
Sketch the magnetic fields of (a) a long wire carrying current out of the page, (b) a flat circular coil whose current is anticlockwise as viewed from one face, and (c) a long solenoid with its north end at the right. Include arrows and distinguish the field inside and outside each coil.
- (a)
Draw the long-wire pattern and direction.
2 marks - (b)
Draw the flat-coil field through and around the coil.
3 marks - (c)
Draw the long-solenoid field inside and outside.
3 marks
Ready to self-mark?Reveal the detailed answer guide
(a)
Draw the long-wire pattern and direction.
Identify what the question is testing, organise the response into distinct mark-earning points, and make every conclusion traceable to a physical principle or to the evidence supplied.
- 1
Concentric circles, anticlockwise for current out of the page.
(b)
Draw the flat-coil field through and around the coil.
Identify what the question is testing, organise the response into distinct mark-earning points, and make every conclusion traceable to a physical principle or to the evidence supplied.
- 1
Through-centre field normal to coil plane and out of the anticlockwise-current face; closed exterior returns.
(c)
Draw the long-solenoid field inside and outside.
Identify what the question is testing, organise the response into distinct mark-earning points, and make every conclusion traceable to a physical principle or to the evidence supplied.
- 1
Nearly uniform rightward internal field, curved external return to the left; appropriate spacing.
Complete marking guidance
Use these worked steps alongside the part-by-part answers. They explain the method and mark allocation; they do not add extra marks.
- Wire: draw circles centred on the current dot and put anticlockwise arrows on them.
- Flat coil: show field through its centre normal to the plane, directed out of the anticlockwise-current face, and returning outside in closed curves.
- Solenoid: show many straight parallel interior lines towards the right/north end; exterior lines curve back to the left/south end.
- Use line spacing to distinguish strong near-wire/interior regions from weaker exterior regions; do not end field lines at a magnetic pole.
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