Ohm's Law: Electrical Conductivity and Resistence

936 Words2 Pages
bulb-icon

Recommended: Factors affecting the resistance of wire conductivity

Numerous factors influence electrical conductivity and resistance, two of them are temperature and length of the wire (these are external factors). Electrical conductivity is defined as the property used to describe how well materials allow electrons to flow, and the degree to which a specific material conducts electricity., Electrical conductivity is calculated as the ratio of the current density in the material to the electric field that causes the flow of current. The SI unit of electrical conductivity is Siemens per meter (S/m). Electrical conductivity is also commonly represented by the Greek letter σ (sigma), but κ (kappa) (especially in electrical engineering) or γ (gamma) are alsowhich are occasionally used. Electrical resistivity quantifies how strongly a specific material opposes the flow of electric current. Electrical resistivity is commonly represented by the Greek letter ρ (rho). The SI unit of electrical resistivity is the ohm⋅metre (Ω⋅m) although other units like ohm⋅centimetre (Ω⋅cm) are also in use.
There are formulas to calculate electrical conductivity and resistivity. Conductivity is defined as the inverse of resistivity (a high conductivity means a low resistance), I=V/R or current equals voltage over resistance. This is known as Ohm’s Law. Electrical resistance is calculated by the formula, R=V/I or resistance equals voltage over current. Ohm’s law however does not hold true if temperature changes. Materials that obey Ohm’s law are known as ohmic or linear because the potential difference across it varies linearly with the current. In addition, whether or not a material obeys Ohm’s law its resistance can be described in bulk resistivity. Furthermore, over sizable ranges of temperature, this temperature depe...

... middle of paper ...

...ature, for example if temperature increases, the resistance, and conductivity value change.
3. Ohm’s Law is also subject to a specific amount of pressure on the substance. For example placing a conductor under tension (a form of strain), causes the length of the section of conductor under tension to increase causing the cross-sectional area to decrease, hence changing the value of resistivity and conductivity.
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.
The objective of this study is to evaluate the effects of wire length and temperature of wire on electrical conductivity and resistivity.

Show More
Related

  • Investigation Into the Resistivity of a Wire

    1884 Words  | 4 Pages

    I also decided to use a wooden block to keep hold of the wire, because

    Read More

  • Flubber

    481 Words  | 1 Pages

    The first term that I noted during the movie was Conductive Polymers. Conductive polymers are almost always organic meaning a large class of chemical compounds whose molecules contain carbon. These polymers have extended delocalized bonds which are bonds found in a molecule that do not belong to a single atom or covalent bond. They are conjugated systems of double bonds and in a aromatic systems. The conjugated systems are atoms covalently bonded with alternating single and double bonds. When the electrons are removed or added into the valence bands the electrical conductivity increases. The conductive polymer has a low conductivity until the electron is removed from the valence band called (p-doping) or (n-doping) until it becomes more conductive. The movement of the charges is what is responsible for electrical conductivity. These polymers are plastic which are organic polymers and with mechanical properties such as flexibility and elasticity.

    Read More

  • Investigating Which Metal Combination Gives Out the Most Voltage in a Solution

    919 Words  | 2 Pages

    Metals contain a sea of electrons (which are negatively charged) and which flow throughout the metal. This is what allows electric current to flow so well in all metals. An electrode is a component of an electric circuit that connects the wiring of the circuit to a gas or electrolyte. A compound that conducts in a solution is called an electrolyte. The electrically positive electrode is called the anode and the negative electrode the cathode.

    Read More

  • The Invention And Effective Invention Of Teflon

    1072 Words  | 3 Pages

    Studies have shown that big changes in temperature do not affect the capability of insulation. In one experiment, materials were set to a high heat of 300 degrees Celsius. After six months in this environment, the substances were cooled to room temperature. The dielectric constant showing the level of insulation had not changed ("Teflon PTFE fluoropolymer resin" 28).

    Read More

  • Kevlar Aramid Fiber

    736 Words  | 2 Pages

    These include, high strength, low weight, high chemical resistance and high cut resistance. This material does not corrode or rust and is also unaffected when placed in or under water.

    Read More

  • Heat Capacity of An Unknown Metal

    1176 Words  | 3 Pages

    Since all metals have different densities and makeups I think that the heat capacity will greatly vary. The makeup of iron is very different than aluminum so the heat capacity will be quite different. Also, a lot of metals are not completely pure and that will also have some effect on the heat capacity.

    Read More

  • Ohm's Law

    976 Words  | 2 Pages

    6. Repeat steps 4, and 5 until at least five 8 sets of readings have

    Read More

  • Investigating the Effect the Thickness of a Wire has On Its Resistance

    1168 Words  | 3 Pages

    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.. =

    Read More

  • Factors Affecting the Resistance of a Wire

    890 Words  | 2 Pages

    I have done a diagram below to help me understand this. Material/resistivity : Different wires composed of different metals will have differing

    Read More

  • Thermal Energy

    569 Words  | 2 Pages

    When we place two objects with different temperatures in contact with each other, the heat from the hotter object will immediately and automatically flow to the colder object. This is known as conduction. Some objects make excellent conductors of heat while others make poor conductors of heat or excellent insulators. Silver, copper, and gold make excellent conductors of heat. Foams and plastics make good insulators of heat but make poor conductors. Last night for dinner, I made myself a grilled cheese sandwich and a bowl of tomato soup. I heated the soup faster than I cooked the sandwich so I poured the hot soup into a bowl and finished cooking the sandwich. Once I was done cooking, I gabbed the soup bowl and burned my hand. The heat from the soup made the bowl hot. This is an example of conduction.

    Read More

  • The Relationship Between Length, Width and Resistance of a Wire

    2113 Words  | 5 Pages

    L = Length of the conductor(m). A = Area of cross section of the conductor (m2). = the resistivity of the material of which the conductor is made. (Îm) The experimental determination of the resistivity of a material. involves measuring the resistance of a specimen of the material.

    Read More

  • Heat Transfer Essay

    1473 Words  | 3 Pages

    Again, it is the most common means of energy transfer and by understanding exactly what conduction means, we can identify it in some of the simple things we do. For instance, think of a pot placed on the stove, on a hot burner. The burner and the bottom of the pot are obviously touching, therefore the pot begins to heat up and get hot as well. As physical contact is the key element in heat transfer through conduction, we can see how important a role it plays in this situation. Now, say that your food is done, you turn the burner off and grab the handle of the pot, only to find that it is extremely hot as well. Again, we can thank conduction for this- as the heat was transferred through the bottom of the pot to the handle. Another example of conduction can be seen through ironing. We plug in and heat up the iron prior to placing it on the clothing in which we wish to smooth out. Once the iron has heated up, we place it on top of the article of clothing and it then heats up the clothing as well. Again, physical contact between the iron and the shirt show us that conduction plays the role of heat transfer in this scenario too. For a final example of heat transfer through conduction, let’s imagine a child, playing outside in the snow on a rather cold day. Once outside for a bit, he is freezing and decides to come inside. He takes off his snow gear, cuddles up to his father and begins to warm up

    Read More

  • Volume's Effect on a Copper Sulphate Solution

    922 Words  | 2 Pages

    An electrode is a component of an electric circuit that connects the conventional wiring of the circuit to a conducting medium such as an electrolyte or a gas. The electrically positive electrode is called the anode and the negative electrode the cathode. If an anode and a cathode are placed in a solution of an electrolyte and a source of direct current is connected between them, the positive ions in the

    Read More

  • Superconductors and Superconductivity

    1569 Words  | 4 Pages

    Thermal vibrations also increase the resistance so when the temperature is lowered, the thermal vibrations of the atoms decrease and so the electrons are less frequently scattered. In short, the resistance of a metal is dependent on the purity of a metal and its temperature: metals with few impurities reach a superconducting state at low temperatures.

    Read More

  • Importance Of Alluvial Rivers

    1533 Words  | 4 Pages

    Flow velocity, Shear stress, and Unit Stream Power are important characteristics for the measurement of the behavior of the river. Quantification of flow velocity, shear stress, and Unit Stream Power is important both for engineering problems and for ecological assessments. All these characteristics depend on resistance which is due to roughness, area of the flow and slope of the channels and the relation between these four parameters is known as resistance relationship.

    Read More

More about Ohm's Law: Electrical Conductivity and Resistence

Open Document