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. Resistance is measured in Ohms.
Variables
There were three variables that our group was able to choose from; the
length of the wire, the area of the wires cross section (thickness) or
the type of wire (constantan or nichrome). All of these variables are
able to change the resistance of the wire.
Here are my thoughts and predictions on what would happen to the
resistance of the wire as you change the variables. I think that if
you change the length of the wire then the resistance would increase
as the length increased but the current would decrease. If you changed
the thickness of the wire then the resistance would decrease as the
wire got thicker but the current would increase. If you change the
type of wire then you will receive different results, as there may be
more or less resistance between types of wire.
To study the resistance or wire we experimented on changing the length
of nichrome wire. We measured the volts and amps over 1 metre; I
worked out the resistance using my calculator. We carried out this
experiment 5 times to make the results fair. We let the wire cool down
a bit between doing the experiments, as its temperature did tend to
increase as we got to the end of each experiment.
Analysis
We took a set of practice results before starting the experiment. Here
they are.
Wire
Volts
Amps
Ohms
10cm
2.63
2.53
1.04
50cm
4.16
0.82
5.
The experiment was performed on one subject, a 20-year-old female gymnast that weighed approximately 58.6kg. First, she performed the test with the arm bike, which had 3 stages of 25Watts, 50W, and 75W all lasting 3min each. Before the end of
...red testing at Lectromec showed that contaminants, such as water, lavatory fluid, and metal shavings, can create a bridge that can allow energy to unintentionally transfer between wires with cracked or damaged insulation for as long as 25 minutes without tripping circuit breakers. Specifically, the totalizer gauge’s wires on TWA Flight 800 had been improperly soldered together and had subsequently cracked apart, providing another opportunity for an explosive short circuit. During examination of the gauge at Honeywell, it was determined that electrical energy would cross the crack in the solder between the connector pins when slightly more than 270 volts (less than is used in lighting circuits) was applied to one of the pins. Thus, a short circuit from a higher-voltage wire to any corouted FQIS wiring could result in excess energy being transferred to the CWT.
From this I can tell I can use 3 volts and resistance wire that is
equation V = IR. V - volts, I - current and R - resistance. I plotted
Two electrical wires * Stopwatch * Thermometer Method I put a piece of Elodea Canadensis (pond weed) in a test tube and covered it with water. The test tube was then placed in a beaker with a thermometer so that the water stayed the same temperature, this was then placed in a cardboard box with a bulb attached to a voltmeter by the electrical wires so that I could concentrate how much light the plant got. I varied the voltage (intensity) of the bulb and counted how many bubbles of oxygen were created at each voltage in one minute. I tested each voltage three times for accuracy for a minute each time. Results Preliminary Experiment Amount of bubbles Light intensity (lux)
The Resistance of a Wire Investigation Aim: To investigate how changing the length of a wire affects the resistance. Prediction: I predict that the longer the piece of wire, the greater the resistance will be. This is because the current is resisted by the atoms in the wire. In a longer piece of wire, there would be more atoms for the electrons to collide with and so the resistance would be greater. The shorter piece of wire will have less resistance because their will be less particles causing less collision.
It is also relevant to know of Ohm’s Law, which states that the current through a metallic conductor (e.g. wire) at a constant temperature is proportional to the potential difference (voltage). Therefore V ¸ I is constant. This means that the resistance of a metallic conductor is constant providing that the temperature also remains constant. Furthermore, the resistance of a metal increases as its temperature increases. This is because at higher temperatures, the particles of the conductor are moving around more quickly, thus increasing the likelihood of collisions with the free electrons.
of the atoms, so if there are more or larger atoms then there must be
This is know as resistivity. The factors I can investigate are : Ÿ Temperature Ÿ Length Ÿ Cross-sectional area/width Ÿ Material (resistivity) The factor I shall investigate is the length of a wire. Background Knowledge Resistance is when electrons travelling through the wire are impeded by the atoms within the wire. Since the electrons are charge carriers when they collide with the atoms in the wire less pass through.
Investigating How the Length of the Wire Affects the Resistance of the Current Passing Through Wire
Experimentally, the dependence upon these properties is a straightforward one for a wide range of conditions, and the resistance of a wire can be expressed as: [IMAGE] There are a few things that determine the current produced; * In a conductor, electric current can flow freely, in an insulator it cannot. Metals such as copper typify conductors, while most non-metallic solids are said to be good insulators, having extremely high resistance to the flow of charge through them. Conductor implies that the outer electrons of the atoms are loosely bound and free to move through the material.
The Length of a Wire and Its Effect on Resistance Introduction: In an electrical circuit, the current (flow rate of charge) depends on the battery voltage that causes the charge to flow through the circuit and the components in the circuit. A circuit consists of a bulb, a battery and a resistor. The bulb is like a resistor, it slows down the electrons and the battery pushes the electrons and gives them energy. A component is a resistor, it slows down the flow of electrons. The bulb acts as a resistor because inside the bulb is a thin filament wire, and so not many electrons can flow through this then slows them down.
I tested all the wires at 3 volts, first I set up the equipment as
V(voltage) I (current) Therefore, I = V R Therefore, if V is constant, in order to increase I, R must decrease.
Temperature- As the temperature increases, the resistance also increases because as the wire heats up the protons start vibrating and