# Questions on electricity were asked by Gavin (10), Tegan (10) and Hayden (9)

Gavin asked “Why does the energy flow through the wires?”

Tegan asked “How does electricity work?”

Hayden asked “How do batteries springs and wires make a complete circuit?”

So how does this compare with a modern day battery. lets have a look and think about Gavins question.

Hayden and Tegan. In the circuit below the  energy flows around the circuit when the switch is closed. Why? What are wires made of? What is special? If the wires were plastic do you think electricity would be able to pass through it? Try and make your own circuits with different materials.

Electricity is linked to the passage of negatively charged electrons. These were very comfortable in the battery until it was connected to a circuit (a circuit is a continuous pathway) and the switch was closed. The circuit gave the electrons (negatively charged) a passage to the positively charged end of the battery. Electricity (electrons) flowed and accompanying the electrons was energy. Look at the Science Master Special on Energy and why not try the Circuit Quiz.

Do not play with mains electricity. It is very dangerous and could kill you.

# Liam (10) asks “Why does electricity go around a circuit?”

Thanks for that team , a very informative introduction. It’s usually the furthest electron that is involved in moving the electrical energy around the circuit.

I have tried to create a small animation to show how this might happen. The ‘pipes’ are the copper metal wire. the dots are the outermost electron attached to the numerous copper atoms. The battery is the ‘motor’ that makes the electrons move. To find out a bit more about how the battery work have a quick look at Sadies question.

Electrons are negatively charged particles so the negative terminal of the battery is ‘pushing’ the electrons while the positive terminal of the battery  is ‘pulling’ the electrons SO when the switch is closed all the electrons in the circuit start moving together.

Who do you think discovered that opposite charges attract and negative charges repel?

Now what about the filament in the bulb. Any idea why that starts producing light? Any thoughts on both these questions, let me know in the ‘Leave a Reply ‘ box.

# Akshita (12) asks “In a circuit of 5 light bulbs and 2 batteries why do all of the light bulbs come on at the same time when you switch the switch?”

Thank you team. You are right metals are much more important than the plastic coating. You could replace the plastic coating with paper or rubber or cloth BUT the metal has to be a metal. Why. It’s all to with things called electrons. Most elements

• An element is a group of atoms that all have the same number of protons (positively charged particles) in their nucleus. Oxygen is the most abundant element on the Earth, Iron is the most abundant metal element.

have electrons that are tightly held by the nucleus but metals are different. The outer electrons of metals are rather loosely held by the nucleus and are free to move around within the metal structure. So if we looked at a circuit which was not connected to a battery (switch is Off) and looked closely at a small section of the wire you would see something like this …

The little red dots depict the outermost electrons of the metal atoms (the element nuclei are the positive circles).  You have to imagine that the electrons are constantly moving around within the metal structure and probably keeping quite close to their parent atom.

Now close the switch.

The battery is now pushing the electrons around the wire (- to +). This push is a bit like a long chain being pushed or pulled. All the electrons in the wire experience the push simultaneously (like the links in the chain) so when the switch is closed all the lights in the circuit will experience the ‘push’ and the electrons in the vicinity of the bulb filament will give up some of the energy of the push to the filament which will be converted to heat energy and create a hot filament which is then partly converted to light energy.

# How did people find out electricity was travelling through the wires while experimenting with them?

Mo from 6K asked this question.

Mo, this is not a question that I am going to ask my friends to answer. I am myself, having difficulty in answering it. If there wasn’t this thing called electricity travelling from the battery to the bulb, the bulb would not light up.

What early experimenters would have found out was that electricity travelled best through metals. So what is special about metals? In 1897 (over two hundred years ago) a scientist called Thompson discovered a small particle called an ‘electron’ . It was found that all materials contain atoms, and atoms contain electrons but in metals some of the electrons are loosely attached to the atom. This allows the battery to push the loosely attached electrons from one metal atom to another thus delivering energy to the light bulb along the metal wire. For some thoughts on Energy go to Light and Energy

To test this create a circuit like the one below. Test different objects, like paper, rocks, plastic and the lead and wood in a pencil and the different metals, a coin, a bit of wire,  a paper clip ….. and find out if metals are really special.

As you ask more questions and find out more answers to your questions, by observation and experiment, you will begin to fully understand the above answer to your excellent question.

DO NOT TRY TO DO THIS WITH MAINS ELECTRICITY. IT IS DANGEROUS.

# Abdur of 6K asked – If you had a solar powered light bulb and you were in a dark room, could you make a circuit with batteries and wires to make it work?

I asked my friends to look at this.

I liked the circuit that my friends made however ….just to let you know, the symbol for a solar cell is:

Which one do you like, the one my friends used or the official one? You can vote by clicking on the Reply button below and giving me your answer.

The really testing part of this experiment is where will you put the switch to test that the solar cell, in the dark, is not making the bulb light up? Unsure – then

REMEMBER DO NOT EXPERIMENT WITH MAINS ELECTRICITY.

# Tabia (9) asks “Why do some circuits not work?”

Tabia, I asked my friends to help me with this question. They had some interesting thoughts.

What my friends have done is to create something called a ‘Short Circuit’. Because the electricity has found a much easier path around the circuit it does not pass through the bulb (where it would have to do work). It takes the shortest route around the circuit. Try making some of these circuits in school. Instead of a light bulb use a motor or a buzzer (do you know their symbols?). Maybe put a switch in the circuit so you get rid of the short route. Have you another question? Why not go to

and ask it. You could also try the Circuits Quiz.

DO NOT DO ANY EXPERIMENTS  USING MAINS ELECTRICITY.

Also

DO NOT USE RECHARGEABLE BATTERIES FOR THESE EXPERIMENTS (The battery will get very hot)