Investigating How Different Lengths of Wire Affect the Resistance in a Circuit
Hypothesis: I predict that; the longer the wire, the more resistance
there will be. So if the length of the wire were to double, so would
the resistance. The reason for my prediction is: The flow of electrons
is called a current, the electrons are constantly hitting atoms, which
causes resistance. If the same amount of current is passed through a
longer piece of wire, there will be more collisions, hence more
resistance.
The more resistance there is, the more volts would be needed to push
the current around the circuit, so the longer the wire, the higher the
current. I can check the voltage, current and resistance to prove that
my hypothesis is correct by using ohms law which is V=I*R (V=volts,
I=amps and R = resistance). I can re-arrange this formula to find the
resistance by saying R=V/I, so when I record my results, I should
divide the volts by the current to give me the resistance. The voltage
and the resistance are directly proportional.
Equipment:
A voltammeter.
An ammeter.
A thin piece of wire attached to a wooden ruler.
Connecting wires with crocodile clips.
A power pack.
Method:
Step 1: I will set up a circuit with a power pack, a voltammeter, and
an ammeter.
Step 2: I will attach a piece of thin wire to a meter long ruler.
Step 3: I will have one plastic coated wire fixed to where the thin
wire is at 0cm on the meter stick.
Step 4: I will then crocodile clip the other plastic coated wire to my
first chosen length on the thin wire which is attached to the meter
stick.
Step 5: I will record the length, the reading on the voltammeter and
the reading on the ammeter, and then work out the resistance, using
ohms law (dividing the volts by the amps).
Step 6: I will then repeat this using different lengths each time, and
I will start with 0.5 amps, working systematically, I will note
Step4: Put flour on a surface and roll the dough until its ¼ in thickness.
This shows that there is a difference of 2cm between A and B, and B
= = = = The first step was to carry out some preliminary tests to establish the best set up for our apparatus.
I will be increasing the square cut out by 1cm until I reach a point
Mark 20 meters on the ground outside on the AstroTurf using a fire glass long tape. (Start to finish)
Scalpel 7. Ruler 8. Wooden Board 9. Measuring Cylinder-size (250cm3) 10. Top-pan Balance 11.
I also decided to use a wooden block to keep hold of the wire, because
I am going to begin by looking into going up in 0.1cm from 0cm being
Resistance of a Wire Introduction Resistance is the opposition a material offers to the flow of electricity. The electrical resistance of an object is not only by what material it's made of, but also by its shape. A very thin copper wire has more resistance than a thick copper wire of the same length. A very long copper wire has more resistance than a short one of the same thickness.
F Another wire, or exact same properties (Nickel Chrome, thickness 34). mm and length 30cm) was placed on top of the previous wire, in the same position, both straight and flat. F. The power was turned on again and the same procedure was repeated. recording current and voltage at three points on the variable. resistor.
Cross-sectional area/ width: If the cross sectional area is increased there is more space for the electrons to move freely making less collisions so more current will pass through making the resistance decreased. I have done a diagram below. [IMAGE] [IMAGE] Small wire Large wire Length: If the length of a wire is increased there are more atoms for the electrons to collide with. There for less gets through meaning the current is less so the resistance is increased.
-Voltmeter -Variable resistor -Power Supply -Various diameters of wire -Crocodile clips -Metre ruler [ IMAGE] Diagram:.. Secondary Source - (Obtained in A-level PHYSICS by Roger Muncaster). Page 536 - "The 'Page The electrical resistivity of a material is defined by R = L / A Where R = Resistance of some conductor(Î).
We were all given acid and alkali. It is a good source of energy. First we set up the burette. We placed it into a clamp so that is secure and stable. Then we filled it up with 50cm3 of acid.