April 9 1015

We are performing an activity that use only one wire to light a light ball. we connect the wire to one side of the ball and battary and attach the other side of the light ball to the battery 

We use this equipment to examine charge. Later, we use a battary to touch this equipment to see if the end of it will separate.

This is our prediction that use the battery to touch the equipment will not make the end of the equipment have any reaction

We derive drive the relationship between current, area, charge and drift velocity, which is the velocity charging particles move. 

We set up the equipment, and connect them to computer. We use logo pro to collect data to determine the relationship between potential difference and current.

By graph those data we have, we find that there is a linear relationship between Potential difference and current.

This is our prediction that the how current-potential difference graph will look like, and this mathes our result. 

We then use the equipment to determine relationship between resistance, current and potential difference. At this time, we apply a new equipment to measure the value of the resistor. 

In the end, we derive that resistance is apporiate to the ratio between potential deifference and current. Also, we are introduced a new formula that tells the relationship between resistance and the resistor's length and area.

Summary: in order to make current in circuit, the circuit must be close and completed. The relationship between R, V and I is R = V/I. However, R is not influenced by V and I, it is only determined by its material, length and cross area.