# Magnetism

IQ: How do magnetized and magnetic objects interact?

• Investigate and describe qualitatively the force produced between magnetised and magnetic materials in the context of ferromagnetic materials
• Use magnetic field lines to model qualitatively the direction and strength of magnetic fields produced by magnets, current-carrying wires and solenoids and relate these fields to their effect on magnetic materials that are placed within them
• Conduct investigations into and describe quantitatively the magnetic fields produced by wires and solenoids, including:
• 𝐵 =𝜇0𝐼/2𝜋𝑟
• 𝐵 =𝜇0𝑁𝐼/𝐿
• Investigate and explain the process by which ferromagnetic materials become magnetised
• Apply models to represent qualitatively and describe quantitatively the features of magnetic fields

Learn.

Master.

Question 1.

a)

Explain what happens when a current carrying conductor is wrapped around a steel nail, include a diagram in your response.[3 marks]

b)

Compare and contrast a solenoid, ferromagnet and a permanent magnet [3 marks]

c)

Demonstrate the interaction of magnetic field lines to demonstrate permanent magnets being attracted together and repelled. [2 marks]

Question 2.

Describe the magnetic field created around a current carrying conductor, use a formula in your answer. [3 marks]

Question 3.

Outline what will happen when the following changes are made in a solonoid.

a) The current is increased [2 marks]

b) The number of coils are increased [1 mark]

c) A lump of iron is added to the inside of the solenoid [2 marks]

Question 4.

What is the magnetic field strength around a wire with a voltage of 3 V, a resistance of 4 ohms and a diameter of 1 cm [3 marks]

Question 5.

A solenoid has 100 coils of wire, with a length of 10 cm, what current is required to create a magnetic field strength of 1 kT