Experiment on Pencil Resister Effect on Circuit Output

try on draw Resister Effect on Circuit OutputContents (Jump to)Research Background hear 1 Metallic Bonding human body 2 Molecular structure of diamond and graphite catch 3 Graphite grading scaleFigure 4 granting immunity proportional to lengthFigure 5 Resistance proportional to fall guy sectional surface areaAim try 1Experiment 2Experiment 3HypothesisExperiment 1Experiment 2Experiment 3Justification of theoryExperiment 1Experiment 2Experiment 3MaterialsMethodExperiment 1 (length)Experiment 2 (cross sectional area)Experiment 3 (type of draw)Diagram of the experimentOhms natural lawVariablesIndep subvertent VariablesDependent VariablesControlled VariablesResultsTable 1 Experiment 1 (length)Table 2 Experiment 2 (cross sectional area)Table 2 Experiment 3 (pencil type)DiscussionExperiment 1Experiment 2Experiment 3Research BackgroundThe electrical conductivity of a substance is a beat of the ease with which the valency electrons actuate byout its structure, and thus is dictated by its bonding. Metallic bonding produces the grea campaign conductivity, as it involves a lattice of positively charged nuclei, with electrons free to move throughout the lattice (Science Daily, 2010).Figure 1 Metallic BondingHence, when an electrical charge is applied to the metal, the electrons are able to easily move through it and therefore it bottom be said to be a good manager. Substances bound by covalent bonding, on the former(a) hand, are normally poor music directors (called insulators) as the electrons are tightly held within the covalent bonds. They are materials that do not permit the free flow of electrons. plot a conductor lets the flow electrons pass through and an insulator impede the flow of electrons. A resistivitys oppositeness limits the flow of electrons throughout the lap. The electrical tubes ability to reduce the up-to-the-minute is called apology and is measured in units of ohms (symbol ). Resistance is caused by the collisions of the electrons wit h positive ions in the lattice.Ohms LawThe resistors current(I)in amps (A) is cost to the resistors potential differenceVin volts (V) divided by the resistanceRin ohms ()Electrical current (Amps) is the drift at which charged particles move from angiotensin-converting enzyme part of the conductor to another current has the symbol I. Voltage is a measure of the difference inelectrical energybetween both separate of a circuit. The bigger the difference in energy, the bigger the voltage.An ohmic resistor obeys the ohms law. Ohms law states that the proportional energy drop across a resistor is proportional to its resistance and the current the flows through is. This can be represented in the form of a formulaV=IRSo, if a current of 1 A is passing through a conductor of resistance of 1 the potential difference between the ends of the conductor leave al matchless be 1V. Additionally, resistance is equal to voltage divided by current, and voltage is equal to current multiply by res istance. Therefore, in a circuit, if a resistors resistance is equal to voltage divided by current, the resistor is ohmic. resistance is the measure of resistance inherent to a particular material.Provided that the dimensions (length and cross sectional area) of any conductor do not change, its resistance will remain the same. If two conductors of exactly the same dimensions have a different resistance, they must be made of different materials. Resistivity is given the symbol () called rho. The resistivity of a material is defined as the resistance of a piece of material having a length of one pulse and a cross sectional area of one square metre.Graphite is a pure carbon substance, where three of its valence electrons are covalently bonded to three other carbon molecules, forming a layered structure. However, the fourth valence electron is left unbonded, and thus is able to move freely. These valence electrons allow the flow of electricity through the substance in certain directio ns when an electrical current is applied to graphite.Figure 2 Molecular structure of diamond and graphiteEach carbon atom in graphite is covalently bonded to three neighboring carbon atoms and these form layers of hexagonal network which are separated by a large distance. Although the fourth valence electrons are remained free which enables the electrons to flow through graphite this makes graphite a good conductor of electricity. Although this does not happen in diamond, for each one of the carbon atoms in diamond makes bonds with four other carbon atoms. So there is no free electron with carbon atoms to conduct electricity blocking the flow of electrons.Figure 3 Graphite grading scaleThe lead in pencil is made up of a combination of graphite and cadaver, with wax and other additives in small quantities. Clay, unlike graphite, is an insulator as it does not conduct electricity considerably, due to the covalent bonds holding valence electrons tightly in place. This is because cla y is chiefly made out of silicate minerals these minerals have very low conductivity which makes them good insulator. The shade of pencil is dependent on percentage of each component. pencils range from 9H, with 41% graphite and 53% clay, to 9B, with 93% graphite and 2% clay.Given that graphite is more semiconducting than clay, as the concent ration of graphite ontogenys, the conductivity should increase. The resistance of an object, a measure of the conductivity of a circuit component, this can be calculated using Ohms law explained before above, which considers electrical resistance as the ratio of the voltage applied to the current which flows through it, or the degree to which the voltage is resisted.Factors that would be affect the resistance of the graphite are length, cross sectional area and temperature. As the length of the conductor is shorter it would allow more electrons to pass through at a taller rate rather than a longer one. While as the radius of the cross secti onal area of a conductor (or thickness) is wider the more electrons can pass through compared to a narrower conductor restricting high rate of flow of electrons. Finally, although temperature would not be tested as it would have less effect on the resistance of the conductor. As the temperature of the conductor increase stronger the resistance as the protons inside the conductor would be vibrating slowing the flow of electrons.Resistance isproportional to length. If the pencils resistor has a different length and give each a particular potential difference across its ends, the longer the pencils resistor the less volts each centimetre of it will get. A small potential gradient in the graph would have fewer volts per metre means current decreases with increased length and resistance increases.Figure 4 Resistance proportional to lengthFigure 5 Resistance proportional to cross sectional areaResistance isinversely proportional to cross sectional area. The bigger the cross sectional are a of the pencils resistor the greater the number of flow of electrons can pass through the conductor. If the length of the pencils resistor does not change the conductor still gets the same number of volts across the potential gradient does not change and so the average drift fastness of individual electrons does not change.AimExperiment 1The aim of this experiment is to test if the length of a pencil resistor affects the output of the circuit.Experiment 2The aim of this experiment is to test if the cross sectional area of a pencil resistor affects the output of the circuit.Experiment 3The aim of this experiment is to test if the type of a pencil resistor (HB, 2H, 2B and 6B) affects the output of the circuit.HypothesisExperiment 1It is predicted that the longer the length of a pencils resistor the get down the current as the electrons would have to travel further which gives a higher resistance.Experiment 2It is predicted that the thicker the cross sectional area of the pencils re sistor the more electrons would flow through which gives a low resistance.Experiment 3It is predicted that as the concentration of clay in the pencils resistor increases, the resistance increases.Justification of supposalExperiment 1As the length of a conductor increases, the resistance increases. Increasing the length of the graphite in the pencil will increase the resistance of the whole circuit. As the resistance through the pencil increases, more voltage is used there and the potential energy across the circuit decreases.Experiment 2As the cross sectional area of the conductor increases, the resistance decreases. As the radius of the cross sectional area of a conductor (or thickness) is wider, the more electrons can pass through compared to a narrower conductor restricting high rate of flow of electrons.Experiment 3Graphite is more conductive than clay, as the concentration of clay in the pencils resistor increases, the resistance increases. Clay compared to graphite is an insu lator and does not conduct with electricity intumesce blocking the flow of electrons. This shows that a 2B would be more conductive than a HB as it contains more graphite than clay.Materialspencils (HB,2H,2B,6B)x3(HB),x3(2H),x3(2B),x3(6B)Insulated alligator clip setX6 provide supplyX1Multimeter (Amp meter and Volt meter)X2Ruler (30cm)X1MethodExperiment 1 (length)The circuit was setup using two alligator clips, in a former bombing. Then one wire was attached to one end of the terminal of the battery and the other end of the wire was attached on to one end of the pencils graphite. Next, the seconds wire was attached to the other end of the terminal of the battery and the other end of the wire was attached into one end of the pencils graphite. Finally, the two multimeter was placed next to the pencil and the two wires from the multimeters were attached on to the ends of the pencil. The circuit was tested with different lengths of pencils. Then the experiment was enter in a dodge a nd graph.Experiment 2 (cross sectional area)The circuit was setup using two alligator clips, in a power battery. Then one wire was attached to one end of the terminal of the battery and the other end of the wire was attached on to one end of the pencils graphite. Next, the seconds wire was attached to the other end of the terminal of the battery and the other end of the wire was attached into one end of the pencils graphite. Finally, the two multimeter was placed next to the pencil and the two wires from the multimeters were attached on to the ends of the pencil. The circuit was tested with different cross sectional area of pencils. Then the experiment was recorded in a table and graph.Experiment 3 (type of pencil)The circuit was setup using two alligator clips, in a power battery. Then one wire was attached to one end of the terminal of the battery and the other end of the wire was attached on to one end of the pencils graphite. Next, the seconds wire was attached to the other end of the terminal of the battery and the other end of the wire was attached into one end of the pencils graphite. Finally, the two multimeter was placed next to the pencil and the two wires from the multimeters were attached on to the ends of the pencil. The circuit was tested comparing HB, 2H, 2B and 6B. Then the experiment was recorded in a table and graph.Diagram of the experimentOhms LawThe resistance was then measured by dividing the total voltage (V) and the current (I).Examplepencil 1 (HB 8.5 cm)Variables free VariablesThe resistor (pencil)Dependent VariablesThe volt and the amp meterControlled VariablesThe voltageResultsTable 1 Experiment 1 (length)LengthVoltage of batterytotal voltage (V) authoritative (A)Resistance () draw 1 (HB 8.5cm)2 V1.5 V0.21 A7.14 4 V2.9 V0.41 A7.07 6 V4.4 V0.66 A6.67 8 V6 V0.77 A7.79 Pencil 2 (HB 17.5cm)2 V1.6 V0.1 A16 4 V3.2 V0.2 A16 6 V4.9 V0.28 A17.5 8 V6.8 V0.4 A17 Pencil 3 (HB 11.5cm)2 V2 V0.18 A11.11 4 V4 V0.32 A12.5 6 V6 V0.5 A12 8 V8 V0.73 A10 .96 Pencil 4 (HB 7cm)2 V1.9 V0.27 A7.03 4 V3.9 V0.56 A6.96 6 V5 V0.79 A6.33 8 V6.7 V1.2 A5.58 Total ResistancePencil 17.14 + 7.07 + 6.67 + 7.79 / 4= 7.1675 Pencil 216 + 16 + 17.5 + 17 /4= 16.625 Pencil 311.11 + 12.5 + 12 + 10.96 / 4= 11.6425 Pencil 47.03 + 6.96 + 6.33 + 5.58 /4= 6.475 Pencil 1Pencil 2Pencil 3Pencil 4Table 2 Experiment 2 (cross sectional area)Cross sectional areaVoltage of batterytotal voltage (V)Current (A)Resistance ()Pencil 1 (HB 17.5cm)4 V1.07 V0.15 A16.40 6 V1.53 V0.21 A16.90 8 V1.99 V0.27 A17.19 Pencil 2 (HB 17.5cm)4 V1.55 V0.19 A8.16 6 V2.17 V0.26 A8.35 8 V2.78 V0.33 A8.42 Pencil 3 (HB 17.5cm)4 V2.46 V0.18 A5.94 6 V3.55 V0.27 A5.67 8 V4.64 V0.36 A5.53 Cross Sectional AreaA=2r2Pencil 13.14 x 1 =3.14Pencil 23.14 x 2= 6.28Pencil 33.14 x 3= 9.42Total resistancePencil 116.40 + 16.90 + 17.19 / 3= 16.83 Pencil 28.16 + 8.35 + 8.42 / 3= 8.31 Pencil 35.94 + 5.67 + 5.53 /3= 5.71 Pencil 1Pencil 2Pencil 3Table 2 Experiment 3 (pencil type)Pencil typesVoltage of batterytot al voltage (V)Current (A)Resistance ()Pencil 1 (2H 10.5cm)6V7.35 V0.16 A45.94 8V9.70 V0.20 A48.50 Pencil 2 (2B 10.5cm)6V2.63 V0.35 A7.51 8V3.18 V0.42 A7.57 Pencil 3 (HB 10.5cm)6 V3.18 V0.34 A9.35 8V3.88 V0.40 A9.7 Pencil 4 (6B 10.5cm)6V0.59 V0.41 A1.44 8V0.71 V0.48 A1.48 Total ResistancePencil 148.50 + 45.94 / 2= 47.22 Pencil 27.57 + 7.51 / 2= 7.54 Pencil 39.35 + 9.7 / 2= 9.525 Pencil 41.44 + 1.48 / 2= 1.46 Pencil 1 (2H)Pencil 2 (2B)Pencil 3 (HB)Pencil 4 (6B)DiscussionExperiment 1 According to the data and the graph shown previously it supports the hypothesis for all the experiments. For experiment 1, it supports the hypothesis that as the length increase the resistance increase. Using the ohms law formulaFor Pencil 2 (HB 17.5cm) with an applied volts of 2V, it shows that the total voltage was decrease to 1.6V with a current of 0.1 A and resistance of 16. Compared to Pencil 4 (HB 7cm) with an applied volt of 2V, it shows that the total voltage was decreasing to 1.9V a 0.1 difference in voltage. With a current of 0.27A and a resistance of 7.03 it shows that as the length of the pencil resistor increases the resistance increase. Increasing the length of the graphite in the pencil will increase the resistance of the whole circuit as the flow of electrons would have to travel longer than a short pencil resistor.Experiment 2For experiment 2, referring to the graphs and tables it supports the hypothesis that as the cross section area of the conductor increases, the resistance decrease. For Pencil 1 with an applied of 4V, it shows that the total voltage was decrease to 2.46V with a current of 0.15A and resistance of 16.40 . Compared to Pencil 3 with an applied volt of 4V, it shows that the total voltage was decreasing to 1.55V a 2.58 difference in voltage. With a current of 0.19A and a resistance of 7.03 it shows that as the cross section area of the pencil resistor increases, the resistance decreases. As the radius of the cross sectional area of a conductor (or thi ckness) is wider, the more electrons can pass through compared to a narrower conductor restricting high rate of flow of electrons.Experiment 3For the experiment 3, it supports the hypothesis that as the concentration of clay in the pencils resistor increases, the resistance increases. For Pencil 1 (2H 10.5cm) with an applied volt of 6V, it shows that the total voltage was decrease toGraphite is more conductive than clay, as the concentration of clay in the pencils resistor increases, the resistance increases. Clay compared to graphite is an insulator and does not conduct with electricity well blocking the flow of electrons. This shows that a 2B would be more conductive than a HB as it contains more graphite than clay.