Answer the following question: Fact 1: Aswitch is used to start the flow of current in an electrical circuit. Fact 2: Electricity flows when a circuit is complete. Given the two facts above, what is a purpose of a switch in an electrical circuit?

Options:
1). to reduce magnetic effects;
2). heat production;
3). to annihilate electrons;
4). preventing heat transfer;
5). direct energy;
6). to complete the circuit;
7). heat is produced;
8). to circumvent resistors;
Answer:
6).