Question

which symbol represents a single - pole single - throw push button switch?

Explanation:

A single - pole single - throw (SPST) push - button switch has two terminals and can either make or break an electrical connection when the button is pushed. The first symbol shows a normally open push - button where the contacts are open until the button is pressed to complete the circuit. The second symbol is a single - pole single - throw toggle switch symbol. The third symbol is not a standard SPST push - button symbol.

Answer:

The first symbol.