Science 9 Tech-JAMES.: 2009

Tuesday, April 21, 2009

Measuring Current, Voltage and Resistance in Series and Parallel Circuit

Measuring Current, Voltage and Resistance in Series and Parallel Circuit

Purpose:

to determine patterns and formulas to predict "I", "V" and "R" in series and parallel circuit.

Procedure:

as descibed in BC Science 9 P314-315.

Data & Observation:

Serie

Parallel

Example Calculation:
2.8V=2800mV
V=IR
2800=26(I)
2800/26=I
I=107.7

Questions:

In a short paragraph, explain how current and voltage change in a series circuit.

In the series circuit, the current did not change through out the circuit. Voltage changed depending on the place, the two sides of the batteries had the most potiental difference, the two sides LED light had the second most potiental difference, and the two sides of other light had the least amout of potiental difference.

In a short paragragh, explain how current and voltage change in a parallel circuit.

In a parallel circuit, the potiental difference of two of the light bulbs are the same and the battery has a different potiental difference. Current in a parallel circuit, are different on each one.

What do you notice about resistance in series?

The resisitance in series circuit changes as the voltage changes. As the voltage increse, the resistance will also increase, and as voltage decrese, the resistance will also decrese.

Do you notice an obvious patterns for resistance parallel?

I find that the current of the two light bulbs will add up to the current of the battery, because the current will split in at the two pathway and will rejoin after. Therefore, the current of the two light bulb will add up to the current of the battery.

Conclusion:

In this lad, i learned that the potiental difference of all of the resistors are different in series circuit, and the potiental difference are the same for all of the resistors in a parallel circuit. Also, Current is the same through out the whole series circuit, and it is different through out in a parallel circuit.

Friday, April 17, 2009

Lab 9-1A-April 16

Lab 9-1A p307

Purpose:
To gain an understanding of one flow of elections in a circuit.

Procedure:
As described on p307 of BC Science 9.

Data & Observation:

Questions:
1a) If I was an electron and leaved the negative terminal, there would only be one way to arrive at the positive terminal.
1b) If I was an electron and leaved the negative terminal, I would have to travel through 2 light bulbs.
2) In circuit 1, one of the light bulbs is removed and the other light is off, because the electrons in circuit 1 have one way to go back to the battery.
3a) If I was an electron in circuit 2, there would be 2 ways that I could reach the battery.
3b) In these 2 routes, the electron only needs to pass one light bulb.
4) When one light bulb is removed in circuit 2, the other one is still on, because the electrons have 2 choices on which route to take and two light bulbs takes separate electrons.

Conclusion:

In this lab we confirmed the flow of elections in a circuit by observing light bulb.
In circuit 1, either both light bulb are lit or none of them are lit, because everything is connected and the electrons only have one route to take.
In circuit 2, the two light bulbs are separated, and other light were lit, and they could be lit on their own, because there are two routes that the electrons could take, and the two light bulbs receive different electrons.