IF YOU INCREASE THE VOLTAGE - MORE CURRENT WILL FLOW.
IF YOU INCREASE THE RESISTANCE - LESS CURRENT WILL FLOW (UNLESS YOU INCREASE THE VOLTAGE).' ó`In Metals The Current Is Carried By Electrons
1. Electric current will only flow if there are charges, which can freely move.
2. Metals contain a sea of "Free Electrons" (which are negatively charged). And flow throughout the metal if they are given energy.
3. This is what allows electric current to flow so well in materials.' ó`Resistance Resistance is anything that causes an opposition to the flow of electricity in a circuit. It is used to control the amount of voltage and /or amperage in a circuit. Everything in a circuit causes a resistance (even wire). It is measured in OHMS (Ω). Resistance occurs when the electrons travelling along the wire collide with the atoms of the wire. These collisions slow down the flow of electrons causing resistance. Resistance is a measure of how hard it is to move the electrons through the wire. The resistance of a wire depends on the number of collisions the electrons have with the atoms there will a larger number of collisions which will increase the resistance of the wire. If a length of a wire contains a certain number of atoms, when that length is increased the number of atoms will also increase.
E.g. If there is a wire that is half the length of another wire it would also have half the number of atoms, this means that the electrons will collide with the atoms half the amount of times. Also if the length of the wire is trebled or quadrupled then the resistance would also treble or quadrupled.'
My prediction was derived from this information.
All of this information I collected originated from the Website, "www.studentcentral.co.uk" from encyclopaedias such as "The Oxford Children's Encyclopaedia" and computer encyclopaedias such as "Encarta". óThis scientific information relates to my experiment by stating that the longer the lengths of wire the higher the resistance. óPreliminary Results
Length Of Wire (mm):
Voltage (V):
Current (A):
Resistance (Ω): óTherefore this information supports my prediction that the longer the length of wire the higher the resistance.
Obtaining Evidence: óThe variables I kept the same are: ôThe same material used for the wire, ôThe same cross-sectional area of wire, ôAnd the same temperature of the wire. óThe potential difference from the power pack: 2V.
To decipher what this meant he began by using pieces of metal with electricity to them to charge them. One piece of metal was positive and the other was
equation V = IR. V - volts, I - current and R - resistance. I plotted
resistance from the blood vessels and vessel walls. This resistance results in an increase in cardiac afterload.
Attraction and repulsion between electric charges at the atomic scale explain the structure, properties, and transformations of matter, as well as the contact forces between material objects. (HS-PS2-6)
resistance and blood volume. Cardiac output refers to the amount of blood pumped by the heart
Cook, G., & Cook, J. L. (2010). The world of children. (2nd ed.). Boston, MA: Pearson Education Inc.
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.
Investigating the Effect the Thickness of a Wire has on Its Resistance. Equipment:.. Nickel Wire cut into 10 pieces of 30cm length (Ruler, Pliers). Two crocodile clips Five Pieces of Wire Power Source Variable Resistor Ammeter Volt Meter Method: The.. =
Free electrons also account for three properties most commonly associated with metals: conductivity, malleability and ductility. The flow of electricity is a flow of electrons passing from atom to atom, so the materials that have the most electrons and want to pass them on will be the best conductors. In malleable or ductile elements, the free electrons act as a sort of lubricant, allowing the atoms to slip out of the lattice structure without cracking, smashing or
longer it will take electrons to get to the end of the wire. This is
Table 3. 1 lists expressions for the resistance Coefficient and values for the flow exponent for each of the formulas
E. Current could flow through the complete ring so it was repelled off the iron rod upon placement.
Inversely, to decrease I, R must increase. The value of R depends on how easy it is for the electric charge to pass through the conductor. Therefore to decrease R, the passage must be made easier and to
Electrons have a wave-like nature so an electron moving through a metal can be represented by a plane wave progressing in the same direction. A metal has a crystalline structure with the atoms lying on a repetitive lattice; a plane wave can pass through a perfectly periodic structure without being scattered into other directions. An electron is able to pass through a perfect crystal without any loss of momentum of its original direction. That is why it is important for superconductors to have very low impurities; any fault in the periodicity of the crystal will scatter the electron wave and introduce some resistance. This is called the residual resistance and it is independent of the temperature.
There are formulas to calculate electrical conductivity and resistivity. Conductivity (s) is defined as the inverse of resistivity (a high conductivity means a low resistance), I=V/R or current equals voltage over resistance. Electrical resistance is calculated by the formula, R=V/I or resistance equals voltage over current.