Ferromagnetic cores amplify magnetic fields in electromagnets Steps: - Recall that an electromagnet consists of a coil of wire around a core material to produce a strong magnetic field when current flows. - Identify that the core material must be ferromagnetic to concentrate and strengthen the magnetic field lines. - Evaluate options: non-magnetic metals like aluminium and copper do not enhance the field, while iron and steel are magnetic but iron is preferred for its properties. - Select iron as the standard core material due to its high permeability and ability to magnetize/demagnetize easily. Why C is correct: - Iron is a ferromagnetic material with high magnetic permeability, which multiplies the magnetic field strength according to the formula B = μH (where μ is permeability and H is the magnetic field intensity). Why the others are wrong: - A. Aluminium: Non-ferromagnetic, low permeability, does not amplify the magnetic field. - B. Copper: Non-ferromagnetic conductor used for coils, not cores, as it offers no magnetic enhancement. - D. Steel: Ferromagnetic but retains magnetism (hysteresis), making it unsuitable for electromagnets that need …