🔍 Key Concepts

• Air choke coil construction and purpose in AC circuits • Difference between coils with magnetic cores (iron or ferrite) and coils wound in free air • How an inductor symbol or physical shape changes when a magnetic core is added

💭 Think About

• Look at each figure and decide which ones clearly have an iron or magnetic core inside or around the winding • Ask yourself: an air choke is meant to have what kind of core material—solid iron, laminated steel, ferrite, or no magnetic core at all? • Consider which shape is simply a coil of wire in space versus those built around a core structure

✅ Before You Answer

• Identify which figures show a distinct core material (blocks, laminations, or toroid) versus only wire • Remember that an air-core inductor/choke relies mostly on the magnetic field in air, not in iron or ferrite • Before choosing, eliminate every option that clearly shows a solid or laminated core passing through or surrounding the coil