🔍 Key Concepts

• Contact materials used in switches, relays, and circuit breakers on ships • Properties needed at an electrical contact: conductivity, low resistance, and resistance to arcing/pitting • Why some metals are plated onto others rather than used in bulk

💭 Think About

• Which of these metals is known for very high electrical conductivity and is commonly used in high‑quality electrical contacts? • Think about arcing when contacts open/close under load: which metal stands up best and keeps a clean, low‑resistance surface? • In marine environments, which metal is often used as a thin facing layer on a tougher base metal to improve contact performance?

✅ Before You Answer

• Compare the electrical conductivity of each option (chromium, silver, nickel, titanium). • Consider which metal is commonly mentioned in electrical engineering as a contact or plating material. • Ask yourself which of these metals you’ve seen associated with switch/relay contacts in other technical studies or equipment manuals.