Magnetism and Magnetic Fields | OCR GCSE Combined Science Physics, Foundation tier (J250)

Magnetism and Magnetic Fields

55 questions
3 subtopics
Paper 5 (Physics)
Paper 5 (Physics)

Magnetism and Magnetic Fields is examined in Paper 5 (Physics).

It covers permanent and induced magnets, and magnetic poles; magnetic fields, and the dipping compass; and the magnetic effect of a current, and solenoids.

Sample questions from Magnetism and Magnetic Fields

Answer each one closed book first, then open the answer.

Permanent and induced magnets, and magnetic poles

Describe the field lines in the gap when a north pole and a south pole are placed facing each other.

Show the answer
They run straight across the gap from the north pole to the south pole, linking the two magnets together.
Permanent and induced magnets, and magnetic poles

Why is a steel paperclip attracted to a bar magnet whichever pole is offered to it?

Show the answer
The paperclip becomes an induced magnet with the pole nearest the magnet always opposite to it, so the force is always attraction.
Magnetic fields, and the dipping compass

How does a plotting compass show the direction of a magnetic field at a point?

Show the answer
Its needle turns until the north end points along the field line at that point.
Magnetic fields, and the dipping compass

Explain why the behaviour of a dipping compass is evidence that the Earth's field comes from inside the planet.

Show the answer
The needle points down into the ground, so the field lines must run into the Earth itself rather than come from something outside it.
The magnetic effect of a current, and solenoids

What two things decide the strength of the magnetic field at a point near a straight current-carrying wire?

Show the answer
The size of the current and the distance from the wire.
The magnetic effect of a current, and solenoids

Explain why a solenoid gives a stronger magnetic field than a single straight wire carrying the same current.

Show the answer
The fields produced by all the separate turns line up inside the coil and add together.

The 3 subtopics

One subtopic is one session. Work down the list.

Subtopic	What it covers	Questions
Permanent and induced magnets, and magnetic poles	Attraction and repulsion between poles as a non-contact force, the field lines between like and unlike poles and the neutral point, how the force weakens with distance, permanent and induced magnets, why induced magnetism only attracts, the magnetic metals, and why steel suits permanent magnets and iron suits electromagnets.	17
Magnetic fields, and the dipping compass	What a magnetic field is, where it is strongest and how line spacing shows strength, field direction, plotting a field with a compass or iron filings, the dipping compass and what its dip shows about the field and core of the Earth, and why the magnetic pole in the far north behaves as a south pole.	17
The magnetic effect of a current, and solenoids	Showing that a current has a magnetic effect, the circular field around a straight wire and the right-hand grip rule, how current and distance change the field strength, the field inside and outside a solenoid, ways of making a solenoid stronger, and electromagnets.	21

Magnetism and Magnetic Fields is 55 of the 1,084 questions in the guide.Get the guide, £7

How the guide is worked

Answering a question from memory stores it far better than reading the answer again. The guide runs that as a fixed procedure on one subtopic at a time, about twenty minutes a session.

Step 1 · Closed book
Cover the answers. Work through one subtopic and write down what you can. Leave blanks where you have nothing.
Step 2 · Open book
Go back to the top. Read each printed answer and write it out in full, including the ones you had right.
Step 3 · Closed book again
Same questions, same order, from memory. The gap between pass one and pass three is the session result.

Read the full method, the return schedule and the research behind it.