Acoustic Vehicle Alert Systems [AVAS] for EVs

A: Principle: In chloride-rich, wet environments, galvanic couples dominate long-term degradation. Applied here, road salt bridges dissimilar metals at the housing-to-lead interface, and rising resistance shows up as distortion before outright failure. Distractor B traps engineers who know fatigue drives speakers indoors, but misapply it to a low-stress, corrosion-driven field environment.

A: Principle: Free-field SPL decays by 6 dB for each doubling of distance. Applied here, doubling from 1 m to 2 m yields 62 minus 6, landing at 56 dB(A). Distractor C catches engineers who remember inverse-square law but double-count it in logarithmic units.

A: Principle: Fatigue damage scales with total load cycles, estimated from frequency and time. Applied here, 30 Hz × (8 h/week × 3600 s/h) × ~200 weeks lands near 4×10^7 cycles. Distractor D tempts engineers who forget to convert hours to seconds.

A: Principle: Material pairing should minimize galvanic potential and coating breakdown. Applied here, Zn-Ni plated steel is sacrificial and compatible with e-coated steel in splash zones. Distractor B traps those who overgeneralize stainless as corrosion-proof, ignoring galvanic mismatch.