Why are nickel-cadmium batteries superior to...

🔍 Key Concepts

• Differences between Inmarsat-FBB (FleetBroadband) and Inmarsat-C services (data type, speed, typical uses) • Typical antenna size and type used with Inmarsat-FBB vs Inmarsat-C (parabolic vs non-parabolic, active vs passive) • What rewind capability (cable/antenna stabilization) is used for on certain stabilized shipboard antennas

💭 Think About

• Think about which system (FBB or C) is used for high-speed IP data and voice, and which is for low-speed messaging. Which one would normally need a larger, stabilized dish? • Consider which type of antenna (parabolic dish vs small omnidirectional) would need mechanical stabilization and "rewind" when the ship turns a lot. • For each option, ask yourself: does that service really match that antenna size/type in real life installations you’ve seen or studied?

✅ Before You Answer

• Verify which system, Inmarsat-FBB or Inmarsat-C, typically uses a stabilized parabolic dish on merchant ships. • Verify which system typically uses a small, simple omnidirectional / non-parabolic antenna that doesn’t need mechanical tracking or rewind. • Check that the option you pick consistently matches: service type ↔ antenna size ↔ parabolic vs non-parabolic ↔ need for rewind capability.

Why are nickel-cadmium batteries superior to lead-acid batteries for standby service?

they are able to hold their charge for long periods of time without recharging

they need fewer cells connected in series for the same voltage and require less mounting space

they have higher output voltages for the same number of cells and require no maintenance

they have a lower cost of acquisition

🔍 Key Concepts

💭 Think About

✅ Before You Answer