In Class Assignment- Circuits

In Today's class we worked in groups of 4 to learn more about circuits. We played around with a "special" ping-pong ball that would light up and hum if its circuit was completed. Here is what we found out:

     1.Can you make the energy ball work? What do you think makes it flash and hum?

Yes, we could make the ball flash and hum by completing the gap in the circuit using our hands.

     2.Why do you have to touch both metal contacts to make the ball work?

As mentioned in the previous question, touching both metal contacts bridges the gap in the circuit. Since humans do conduct electricity, the flow is able to resume, thus completing the circuit.

     3. Will the ball light up if you connect the contacts with any material?

No. Only electrical conductors will make the ball light up.

     4. What materials will make the energy ball work? 

When tested, the materials that make the energy ball work were all conductors of electricity, such as metal and the human body.

     5. This ball does not work on certain individuals, what could cause this to happen?

This question had the whole class thinking. We were unsure because the ball worked on everyone in our class. The only reason I could think of was that some people's bodies may not conduct electricity as well as the rest of ours. With further research I have found that water and salt in our bodies cause the conduction of electricity. Maybe some people have a condition where they don't have as much salt/ water in their bodies?

     6. Can you make the energy ball work with 5-6 individuals in your group? Will it work with the entire class?

We experimented with this question and found that it did work with 5-6 people, as long as we were all connected to each other. We also tried this out with the entire class and once again, the ball began to flash and hum. However I do think the strength is weakened when more people stand between the completed circuit.

     7. What kind of circuit can you form with one energy ball?

A series circuit.

     8. Given two balls can you create a circuit where both balls light up?

Yes, to complete this we simply connected our hands as before except the people who had a ball beside them touched a metal connector.

     9. What do you think will happen if one person lets go of the other person's hand and why?

The energy ball stops working. The gap in the circuit now makes this an open circuit.

     10. Does it matter who lets go?

It does not because everyone in the group played a part in the completed circuit.

     11. Can you create a circuit where only one ball lights up? Use both.

This can be attained by forming a parallel circuit. Much like the ones we have in our homes (if one system fails everything else still works). creating a break in the circuit wouldn't affect both balls, just one.

     12. What is the minimum number of people needed to complete this?

A minimum of five people would be needed. 

In conclusion, what is the difference between a series and parallel circuit?

In a series circuit, all the loads are connected one after another in a single path. It is possible for some of the loads to be supplied with current while others are not.

In a parallel circuit, the loads are connected side by side. Thus, any break in the circuit would cause a loss of current to all the loads.