Day 11 Current & Resistance & Voltage 04/07/2014

Light Bulbs & Batteries Experiment:

One Battery

Two Batteries

This is the experiment asked us to find a way to light up the bulb. The first one bulb light up with one battery.

But we want it to be twice lighter, so we add another battery to make it twice lighter. According to the picture above we see 2nd light bulb is twice lighter than first one.

Current:

For this experiment we were ask to choose a resistor to connect to ammeter and power supply. Since we know the voltage by power supply we can measure the resistant inside the resistor which determined by power meter. For each trail we increase the voltage by power supply. Below is our data and other group's.

This data shows that #1's resistant is much larger than #2 . The Voltage on both group are almost similar, but the current on each group has lot difference. 

Here comes the graph

According to the graph above the voltage and current's relationship is linear and proportional. However, the slope of the line is the resistant of resistor by V = RI, so #1 resistor has bigger resistant than #2 for sure.

The reason why #1 has greater resistant is because #1 is a longer resistor which electron need more time to pass through.

Copper & Silver material resistant test:

This is Lab we has given couple coil wrapped around silver and copper with same diameter except one. However there are only one copper then rest are nickle&silver. The goal is to determine the resistant of each coil.

We using the power meter to determine the resistance, and we got 1.9 as our unaffected resistant. 

These data prove that when length get larger the resistance also get larger.

Here are the graph:

The graph again shows the proportional relationship between length and resistance which length increase the resistance also increase.

However the diameter is total different which diameter increase the resistant decrease due to the larger cross sectional area which is inverse relationship between resistance and diameter.