Magnetic attraction and material type – which metal is not attracted by a magnet? Identify the material that is not appreciably attracted by a typical permanent magnet.

Introduction / Context:
Materials respond to magnetic fields in different ways: ferromagnetic (strong attraction and possible permanent magnetization), paramagnetic (weak attraction), and diamagnetic (weak repulsion). Recognizing which everyday metals are ferromagnetic is important for separation, sensing, and design of magnetic devices.

Given Data / Assumptions:

• Permanent magnet producing a moderate static magnetic field.
• Common engineering metals: iron, nickel, cobalt (ferromagnetic); copper (diamagnetic).
• No special alloys or heat treatments that alter magnetic phases are considered.

Concept / Approach:

Iron, nickel, and cobalt are ferromagnetic at room temperature and are strongly attracted by magnets. Copper is diamagnetic with a very small negative susceptibility, meaning it is not attracted and can even exhibit weak repulsion in nonuniform fields. Therefore, among the listed options, copper is the material a magnet does not attract appreciably.

Step-by-Step Solution:

Verification / Alternative check:

Simple experiments show paper clips (steel/iron) cling to magnets, nickel coins may stick depending on composition, while copper wire does not stick. Eddy currents in moving magnets can exert forces on copper, but that is a dynamic effect unrelated to static attraction.

Why Other Options Are Wrong:

Nickel and iron are categorically ferromagnetic and strongly attracted; 'iron and copper' wrongly includes iron; cobalt (not listed as an option originally but provided here for contrast) is also ferromagnetic.

Common Pitfalls:

Confusing dynamic eddy-current braking effects in copper with static magnetic attraction; assuming all metals are attracted by magnets equally.

Final Answer:

copper