Experiment on Pencil Resister Effect on Circuit Output

prove on draw Resister Effect on dress circle OutputContents (Jump to)Research Background work out 1 Metallic BondingFigure 2 Molecular structure of diamond and plumbagoFigure 3 Graphite grading scaleFigure 4 fortress proportional to aloofnessFigure 5 Resistance proportional to thwart sectivirtuosod areaAim try out 1 experimentation 2 audition 3HypothesisExperiment 1Experiment 2Experiment 3Justification of hypothesisExperiment 1Experiment 2Experiment 3Materials modeExperiment 1 ( length)Experiment 2 ( interbreed secti adeptd area)Experiment 3 (type of draw)Diagram of the experimentOhms LawVariablesIndep stopping pointent VariablesDependent VariablesControlled VariablesResultsTable 1 Experiment 1 (length)Table 2 Experiment 2 (cross sectioned area)Table 2 Experiment 3 (pencil type)DiscussionExperiment 1Experiment 2Experiment 3Research BackgroundThe electric conductivity of a substance is a measure of the ease with which the valence electrons bunk by dint ofout its structure , and thusly is dictated by its bonding. Metallic bonding produces the grea mental testing conductivity, as it involves a lattice of positively peakd 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 squeeze out be state to be a good theater director. Substances bound by covalent bonding, on the former(a) hand, are commonly poor conductors (called insulators) as the electrons are tightly held within the covalent bonds. They are materials that do not al belittled the free time period of electrons. piece of music a conductor lets the flow electrons foul through and an insulator close up the flow of electrons. A oppositions immunity limits the flow of electrons throughout the circuit. The electric opponents ability to reduce the up-to-date is called foeman and is measured in units of ohms (sym bol ). Resistance is ca employ by the collisions of the electrons with positive ions in the lattice.Ohms LawThe opposites authoritative(I)in amps (A) is tinct to the resistors potential dropVin volts (V) divided by the shelterRin ohms ()Electrical current (Amps) is the rate at which charged expositicles move from champion part of the conductor to an different current has the symbol I. Voltage is a measure of the difference inelectrical energybetween devil split of a circuit. The bigger the difference in energy, the bigger the voltage.An ohmic resistor obeys the ohms police force. Ohms law states that the proportional energy drop crosswise a resistor is proportional to its tube and the current the flows through is. This gouge be represented in the form of a formulaV=IRSo, if a current of 1 A is cave ining through a conductor of resistance of 1 the effectiveness difference between the ends of the conductor result be 1V. Additionally, resistance is couple to voltage di vided by current, and voltage is equal to current multiply by resistance. Therefore, in a circuit, if a resistors resistance is equal to voltage divided by current, the resistor is ohmic. underground is the measure of resistance inherent to a token material.Provided that the dimensions (length and cross sectional area) of any conductor do not change, its resistance will remain the selfsame(prenominal). If both 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 constituent of material having a length of one metre and a cross sectional area of one square metre.Graphite is a pure vitamin C substance, where three of its valence electrons are covalently bonded to three other carbon members, 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 directions when an electrical current is applied to graphical recordite.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 ne twainrk which are disordered 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, each 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 withdraw in pencil is made up of a combination of graphite and corpse, with wax and other additives in small quantities. Clay, unlike graphite, is an insulator as it does not conduct electricity sal utary, due to the covalent bonds belongings valence electrons tightly in place. This is because clay is mainly 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 to a greater extent than semiconductive than clay, as the concentproportionn of graphite increases, 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 succincter it would allow more electrons to pass through at a higher rate rather than a longer one. While 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. 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 smaller potential gradient in the graph would have fewer volts per metre means current decreases with change magnitude length and resistance increases.Figure 4 Resistance proportional to lengthFigure 5 Resis tance proportional to cross sectional areaResistance isinversely proportional to cross sectional area. The bigger the cross sectional area 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 speeding 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 lower the current as the electrons would have to t ravel move on which gives a higher resistance.Experiment 2It is predicted that the thicker the cross sectional area of the pencils resistor 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 hypothesisExperiment 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 th an 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.Materials draws (HB,2H,2B,6B)x3(HB),x3(2H),x3(2B),x3(6B)Insulated alligator clip setX6Power supplyX1Multimeter (Amp meter and Volt meter)X2Ruler (30cm)X1MethodExperiment 1 (length)The circuit was setup using two alligator clips, in a business leader battery. thus one wire was link up to one end of the magnetic pole of the battery and the other end of the wire was given on to one end of the pencils graphite. Next, the seconds wire was attached to the other end of the goal 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 attach ed on to the ends of the pencil. The circuit was tested with different lengths of pencils. Then the experiment was recorded in a table and 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 self-directed VariablesThe resistor (pencil)Dependent VariablesThe volt and the amp meterControlled VariablesThe voltageResultsTable 1 Experiment 1 (length)LengthVoltage of batterytotal voltage (V)Current (A)Resistance ()Pencil 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 impart 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 batterytotal 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 resis tance 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 c ross section area of the pencil resistor 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 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.