Introduction: First of all, the fundamental basis for much of modern life is the fact that electrical charge flows through a material carried by electrons. For the most part, materials that effectively conduct electricity-- conductors-- are ones that allow electrons to flow freely through them due to their crystalline structure. Materials that restrict the movement of electrons are often classified as insulators; however, the resistivity of substances is not black and white. Instead, it exists as a spectrum between total blockage and no blockage, with many materials lying in between being an insulator and being a conductor. Although the majority of electrons in these atoms stay in place, some move through the material taking the …show more content…
Of course, many factors must be taken into account when choosing the material(s) when producing resistors, including: voltage stress, thermal effects, lifetime, etc. Whether or not the resistor is being used to decrease voltage, produce heat, and/or produce light dictates what you use to measure the efficiency of the resistor. These measurements can range from resistivity(ohms) to temperature(F) even to brightness(lumens) (Kostic, 2013). Due to the fact that in many circuits resistors are primarily used for current limiters, this experiment will measure the resistivity of the resistor in ohms. In order to accurately measure the resistance provided by the different substances we will be using a device called a digital multimeter. A digital multimeter is a device used to calculate volt, amps, and ohms. If the molecular length increases, then the resistivity of the resistor should increase if resistivity is a function of molecular length. Due to the fact that resistivity affects current applied to electronic devices, this experiment will utilize an L.E.D. after the resistor for qualitative data. Throughout the history of electronics, many different materials have been used in resistors, mainly varying
The purpose of this experiment was to classify unknown solids based on their type of chemical bonds by investigating their properties. By using data, Unknown 1 was classified as a metallic. This was because it appeared a shiny copper color, had a very high conductivity as a solid, had a high melting point, and was malleable. Unknown 2 was classified as a nonpolar covalent bond. This was because it had no conductivity as a solid and low conductivity in water.
There are 3 types of metals for electricity conducting: metallic conductor, semiconductor, and superconductor. Metallic conductors allow the free flow of ions and electrons through a sample; and its conductivity decreases as the temperature increases.
Some of these experiments included using electricity to send electrical currents to different materials as well
When a material is conductive, the conductivity probe will have a solid and visible red light. However if it is not conductive there will be no light and if it is a semi-conductor there will be a dim and possibly “flashing” light. If an element reacts with acid it will create bubbles when the sample comes into contact with the acid. Metals will be shiny in luster, malleable, conductive, and they will react with hydrochloric acid to create hydrogen gas. Nonmetals on the other hand will be dull in luster, brittle or not malleable, they will not conductive, and they will not react with acid. Finally, metalloids will will have properties of both nonmetals and
To determine the effect that the voltage will have on the current of a circuit, when one resistor is connected in the circuit.
The patterns in the resist are formed when the resist is developed so that the areas of resist remaining after development protect the substrate regions which they cover.
Microelectromechanical Systems (MEMS) are systems that are designed on a micro metre scale and have become more popular as the demand for devices to get smaller has increased. The main uses of these systems are for sensors, such as accelerometers and gyroscopes and other such devices like microscopy and inkjet nozzles for example. There are many materials that can be used for MEMS as the cost of the material is almost eradicated due to the micro size of the systems being produced. This brings materials such as gold, platinum and diamond can be used, as these materials have some properties which are very desirable for a MEM systems. The most common material that is currently used in MEMS is silicon and silicon based compounds as they
Ohm’s law defines the relationship between three important electrical properties namely: voltage, current and resistance. Mathematically, ohm’s law is expressed as: V=IR. By understanding the importance of conduction, one is able to determine the total resistance and visualize how resistors are connected in parallel circuits. In parallel connection, each resistor provides a separate path for current [I] so that the total resistance of a parallel circuit is reduced as more resistors are connected in parallel. In contrast, the resistance in series circuits increases when more resistors are introduced into the circuit. This
Resistors restrict or limit the flow of current in a circuit. The ability of a material or component to resist current flow is measured in ohms. There are three main types of
The study makes use of both Horizontal Resistivity Profiling (HRP) and Vertical Electrical Sounding (VES). Three(3) HRP data were obtained within the study area using Wenner configuration to give the Electrical Resistivity Tomography (ERT) of the area
resistance. They are inserted into a circuit in order to lower the current of to produce a desired voltage drop. There are two kinds of
Over time, the charge accumulated on a powder surface will partly decay (dissipate) (Malave-Lopez and Peleg, 1985). Charge decay is a complex phenomenon that has been measured by different techniques (Paasi et al., 2001). The timescale for electrostatic charge decay is an important factor. For example, there will be a higher probability of considerable charge build-up on the material when charge decay occurs slowly. The charge decay rate is a measure of the rate at which the electrostatic charge present on the surface of a material can migrate away (Chubb, 2002). The charge decay rate is dependent on many factors, including material’s electrical resistivity, the resistivity of the other material on contact, RH of the surrounding air and hold time (Bailey, 1993; Sharma et al., 2001a). The lower the material electron conductivity the longer the time needed for charge decay. A powder in contact with a conductive material will dissipate the charge quicker than the same powder in contact with an insulator. It is anticipated that moisture adsorption will make the material more conductive. (Paasi et al., 2001) showed the charge decay rate to increase with increasing RH due to a concurrent decrease in surface resistivity. The hold time (defined as the time passed between the end of processing and dispensing the sample into the Faraday cup for charge measurement) was shown as the most effective option of dissipating charge following blending (Engers et al., 2006).
The outer shell of electrons that orbit the nucleus of an atom is called the valance shell. This is what makes a copper atom conduct. For a copper atom the number of electrons is one. When a charge of electricity is placed in the end of a wire the electrons move into the wire. Since there is only one electron in the valance shell of a copper atom it can be easily dislodged with a small amount of energy causing it to jump to the next atom. This will then cause the valance electron of that atom to jump to the next atom and so forth. This movement happens very fast making it possible for a large number of electrons to move through the wire. An example of a conductive atom is shown figure 1.
Typically a lower resistivity layer overlies a more resistive core (Arnason et al., 2008). The low resistivity layer is characterized by an electrically conductive clay (smectite), which forms in temperatures of 70°C. As temperatures increase the proportion of a less conductive clay (illite) increases until the formation of pure illite at 250°C (Anderson et al., 2000). Resistivity of smectitie is typically between 1 and 10 ohm-m compared to the 20 -100 ohm-m resistivity of the clay layers at 180°C (Anderson et al., 2000). Typical resistivity’s outside of geothermal systems vary but are typically between 50-200 ohm-m for volcanic rocks and less than 5 ohm-m for marine sediments (Anderson et al., 2000).
Throughout this research paper, the reader will have a better understanding of the different forms of resistance. Also the reader will have the ability to compare the two types of resistance which were active and passive. And finally the reader will be abl