Which two major causes of corrosion are noted in the context?

The correct answer emphasizes galvanic corrosion and stray current as two major causes of corrosion.

Galvanic corrosion occurs when two dissimilar metals are in electrical contact in the presence of an electrolyte, leading to one metal corroding faster than it otherwise would. This process is driven by the electrochemical potential difference between the metals, which causes the more reactive metal to sacrifice itself to protect the less reactive one. This is a crucial concept in the context of jacks and other metal components, as understanding this phenomenon is essential for selecting appropriate materials and protective measures to prevent premature failure.

Stray current corrosion, on the other hand, results from electrical currents that stray from their intended path. This can happen in environments where electrical equipment is operating, causing unintended electrical flow through the ground or other conductive materials. This stray current can accelerate the corrosion process on metal surfaces, especially if those surfaces are part of critical infrastructure, like jacks. Recognizing how stray currents can lead to localized corrosion helps technicians engineer systems that mitigate such risks.

The other options present causes of wear or environmental factors that may contribute to a general deterioration of materials, but they do not encapsulate the specific electrochemical processes like galvanic and stray current corrosion that are pivotal in the context of