🔍 Key Concepts

• Figure F is an emergency‑stop pushbutton; think about whether it is normally closed (NC) or normally open (NO) in a safety circuit. • Look at the schematic symbols 1–8 and identify which show a pushbutton contact versus a toggle, rotary, or multi‑position switch. • Emergency‑stop devices are usually drawn as an NC contact that opens when pressed; sometimes a dashed or mechanical linkage symbol shows that it is a maintained, lock‑in device.

💭 Think About

• First, decide what the electrical state of an emergency‑stop button should be when it is not pressed. How is power removed if a wire breaks? • Next, among the symbols, which one clearly shows a momentary (pushbutton‑type) contact that is closed in the normal condition and opens when actuated? • Also, do any of the symbols include a dashed line or extra mark indicating a mechanical latch or interlock, typical of an emergency‑stop mushroom?.

✅ Before You Answer

• Verify which symbol represents a pushbutton, not a toggle, selector, or multi‑pole rotary switch. • Confirm that the contact shown is normally closed (NC) in the rest position and opens on operation, matching a fail‑safe E‑stop circuit. • Double‑check that the chosen symbol could reasonably be labeled “EMERGENCY STOP” in a motor‑control or safety circuit diagram.