Generally, how many output contacts do SSRs have?

Solid State Relays (SSRs) typically have one output contact, which is either normally open (NO) or normally closed (NC), depending on the design of the relay. The primary function of an SSR is to control high-power devices by using a low-power input signal, and it achieves this through semiconductor components rather than mechanical contacts.

Having only one output contact is a key characteristic of SSRs, as it simplifies their design and application in various circuit configurations. This allows users to control a single load effectively, making SSRs ideal for applications such as automation, heating elements, and lighting controls, where reliable and rapid switching is essential.

When comparing this to the other options, having two or four output contacts is atypical for standard SSRs. While some specialized relays may contain more than one contact, the fundamental design of SSRs revolves around the use of a single output for controlling a load. Thus, the choice that states SSRs generally have only one output contact aligns with the primary characteristics and functionality of Solid State Relays.