🔍 Key Concepts

• Thermostat contacts are just temperature-actuated switches – think in terms of normally-open (NO) vs normally-closed (NC). • A thermostat that opens on rising temperature is normally closed at normal (lower) temperature and opens when the set temperature is exceeded. • Look for the small graphic added to the basic switch symbol that indicates temperature actuation (often a slanted line or wedge) and note whether the basic contact shown is NO or NC.

💭 Think About

• First, among symbols 1–14, which ones clearly show a basic switch contact (NO or NC) with some extra mark indicating it’s controlled by a condition (temperature, pressure, flow, etc.)? • Of those condition‑controlled switches, can you decide which extra mark most logically represents temperature rather than pressure or flow, by comparing to the physical thermostats shown in views C and D? • Once you’ve isolated the temperature‑type symbols, look closely at the contact itself: is it drawn as closed in its normal state, or open? Remember, a thermostat that opens on rising temperature must be shown closed in its normal (lower temperature) condition.

✅ Before You Answer

• Be sure you can identify which symbols represent normally closed (NC) contacts versus normally open (NO) contacts before choosing. • Confirm that the added shape (triangle, bulb, circle, etc.) matches what you’d expect for a temperature sensing element rather than pressure or flow. • Before picking an answer, double‑check that the symbol you chose shows a closed contact in the normal state that would open when actuated by temperature rise.