Switch facts & stats

Question 1

When a switch in a simple circuit is open, what happens?

Accepted Answer

Current stops flowing. An open switch creates a gap in the circuit, so electric current cannot flow.

Question 2

What is a switch with a lever that flips between on and off positions called?

Accepted Answer

A toggle switch. A toggle switch has a lever that snaps between positions, like many classic light switches.

Question 3

Which tiny semiconductor device works as the electronic switch inside computer chips?

Accepted Answer

Transistor. Transistors switch current on and off, and modern chips contain enormous numbers of them.

Question 4

What is an electrical relay?

Accepted Answer

A switch operated by an electromagnet. In a relay, a small current energises a coil whose magnetism moves contacts to switch a separate circuit.

Question 5

Which safety device automatically switches off a circuit when too much current flows?

Accepted Answer

Circuit breaker. A circuit breaker trips on overcurrent and can be reset, unlike a fuse, which must be replaced.

Question 6

What makes a reed switch open or close?

Accepted Answer

A magnetic field. A reed switch has thin metal reeds sealed in a glass tube that flex to make or break contact when a magnet comes near.

Question 7

A bulb is wired through two switches in series. Which logic operation does this circuit match?

Accepted Answer

AND. Current flows only if both series switches are closed, just as AND is true only when both inputs are true.

The basics