Q) What type of switch is represented by item 3 in figure T2?
A) Single-pole single-throw
A common abreviation designation for single-pole single-throw switch is SPST. The single-pole single-throw switch is the most common on/off switch. The number of "poles" refers to the number of separate circuits which are controlled by the switch. The number of "throws" refers to the number of separate positions that the switch can select.