# Video: Identifying Circuit Symbols

The diagram shows four circuit symbols. Which circuit symbol represents a battery?

01:30

### Video Transcript

The diagram shows four circuit symbols. Which circuit symbol represents a battery?

Well, let’s go through them one by one and see if we can label them all. The first one a looks like it’s got two terminals. Here, that’s the positive one because it’s got the plus sign. And this therefore must be the negative one. This is in fact a cell.

Now it’s really easy to confuse this one with a battery. But remember, a battery is a collection of cells put together end to end. And that’s exactly what diagram b is. This is a cell. This is a cell. And the dotted line suggested there are more in between them.

Of course, there could be any number of cells between these two end ones. Hence, we use the dotted lines. That represents that there could be any number of cells there.

So we’ve got the answer to our question. However, let’s just see if we can label diagram c and d. So diagram c represents what’s known as a diode. A diode’s functionality is to allow current to flow only in one direction. And that’s while this is what the circuit diagram is for a diode, because it allows the current to flow in the direction of the arrow, this way. But it stops current flowing this way.

Therefore, this diagram is of a diode. And finally, there’s option d. This one represents a very common circuit component. It’s the resistor. The squiggly line represents the resistance to the current as it travels through the circuit. So the answer to our question is that diagram b is the circuit symbol for a battery.