🔍 Key Concepts

• Magnetic strainers are designed to trap particles that respond to a magnetic field. • Think about which engine/gear materials are magnetic and which are non‑magnetic. • Reduction gear oil systems often circulate wear particles from gears, shafts, and bearings.

💭 Think About

• Which of the listed materials would actually be attracted by a magnet in real life? • Among the answer choices, which ones are metals, and of those metals, which are typically iron-based? • Consider what kind of wear particles you’d most want to remove from a steel gear train running in lubricating oil.

✅ Before You Answer

• Verify which listed material is iron‑based or steel‑related (ferrous). • Eliminate any choices that cannot be picked up by a magnet. • Remember that a strainer in an oil system is targeting solid metal wear particles, not chemical properties like acidity.