Evaluation on the characteristics of capacitors upon the influence of dielectric constants

Transcription

1 Current Science Perspectives 4(4) (2018) Evaluation on the characteristics of capacitors upon the influence of dielectric constants Chukwuemeka Peter Ukpaka Department of Chemical/Petrochemical Engineering, Rivers State University, Port Harcourt, Nigeria *Corresponding author s chukwuemeka24@yahoo.com, peter.ukpaka@ust.edu.ng A R T I C L E I N F O A B S T R A C T Article type: Research article Article history: Received July 2017 Accepted June 2018 October 2018 Issue Keywords: Evaluation Characteristics Capacitors Influence Dielectric constants Material used to insulate an electric field from the environment must have the property of dielectric composition. The electrical insulators must possess a high electrical resistivity, high dielectric strength and also low loss factor. A high dielectric strength prevents catastrophic breakdown of insulator at high voltages, The internal failure of the insulators occurs if impurities provide donor or acceptor levels that permit electrons to be excited into conduction band, while External failure is caused by arcing along the surface of the insulator or through interconnected porosity within the insulator body. High electrical resistivity which results from the large energy gap between the valence and conduction band, prevent current leakage. However, small dielectric constant prevents polarization of the system, whereas in this case, charge is not stored locally at the insulator. Low dielectric constants are desirable for insulators but high dielectric constants are required for capacitor. Therefore dielectric used for capacitor should exhibit a large degree of polarization over a wide range of temperature and frequency. The research demonstrates the usefulness of the characteristics of material composition for production of dielectric components International Scientific ganization: All rights reserved. Capsule Summary: This research demonstrates the characteristics of capacitors upon the influence of dielectric constants as well as the contributing factors in terms of internal failure and a high dielectric strength prevents catastrophic breakdown of insulator at high voltages. Cite This Article As: C. P. Ukpaka. Evaluation on the characteristics of capacitors upon the influence of dielectric constants. Current Science Perspectives 4(4) (2018) INTRODUCTION Two important applications of dielectric materials are insulators and capacitors. Insulators are used to prevent the transfer of charge in an electric circuit, such insulating materials include; plastic covering on electric wire and ceramic bell used in high voltage power line (Guy et al. 1972). Capacitors are electronic components that store, filter and regulate electrical energy and current flow and are one of the essential passive components used in circuit boards. Capacitors are primary used for uttering electrical charges, conducting, Alternating Current (AC), and blocking or separating different voltage levels of Direct Current (DC) source (Robert, 1980). Capacitor are one type of components, there are many types of capacitors that are differentiated by the materials used in constructing them, each providing unique features and benefit. Understanding basic capacitor construction and how different materials can affect their characteristics will aid in choosing the proper capacitor for a given application (Giore et al. 2005). The unit of capacitance in the farad. For 1 farad of capacitance, I coulomb of charge is stored on the plates when I volt is applied. If 1 Farad = I 37 editorcsp@bosaljournals.com

2 Fig. 1: Basic structure of capacitor (John et al. 2007) Fig. 2: A Simple Illustration of Capacitor Shape Characteristics (Carlson and Illman, 1994) coulomb/1 volt, 1 coulomb represents 6 x electrons. Dielectric constant is charge Q (coulombs) that can be stored by a capacitor is given as: Q = CV, where V is the voltage across the plates of the capacitor, C is the capacitance, Q is the charge. Therefore dielectric used for capacitors should exhibit a large degree polarization over a wide range of temperature and frequency. Dielectric properties and electrical insulators are materials used to insulate an electric field from the surroundings must be dielectric. Electrical insulators must possess a high electrical resistivity with a high dielectric strength and low loss factor (David et al. 2001). High electrical resistivity results from the large energy gap between the valance and conduction bands prevent current leakage (Sheldon and Robert, 1982). A high dielectric strength prevents catastrophic breakdown of the insulator at high voltages, Internal failure of the insulator occurs if impurities provide donor or acceptor levels that permit electrons to be excited into the conduction band External failure is caused by arcing along the surface of the insulator or through interconnected porosity within the insulator body (John and Anthony, 1994). In particular, absorbed moisture on the surface of ceramic insulators presents a problem. A Glass or ceramic insulator seal off porosity and reduces the effect of surface contaminants. The small dielectric constant prevents polarization, so charge is not stored locally at the insulator (John and Anthony, 1994). Low dielectric constants are desirable for insulators, but high dielectric constants are required for capacitors (John and Anthony, 1994). Dielectrics used for capacitors should exhibit a large degree polarization over a wide range of temperature and frequencies. Several important factors influence dielectric behavior of materials. All dielectric that are effective have a high electrical sensitivity to prevent leakage or discharge of the store energy (electrical sensitivity). The common dielectric have resistivity of Ohms ( ) meter or greater. Most of the dielectric materials for capacitors fall into one of the three groups namely: liquids composed of polar molecules, polymers and certain ceramics. All possess permanent dipoles that move easily in an electric field yet still produce high dielectric constants (Ezong and Lim, 2002). Water, which has a high dielectric constant, is corrosive, relatively conductive and difficult to use in constructing capacitors devices. These material constant relatively long chainlike molecules that serve as dipoles yet are easily aligned. Often they are impregnated into paper, which itself is a dielectric (Ezong and Lim, 2002). In amorphous polymers, segments of the chain possess sufficient mobility to cause polarization. Capacitors frequently use polyester (such as Mylar), polystyrene, polycarbonate and cellulose (paper) as dielectric. Glass, an amorphous ceramic behaves in much the same way, Glassy polymers and crystalline materials have lower dielectric constants and dielectric strengths than their amorphous counterparts. Polymers with asymmetrical chains, have a high dielectric constant even though the chains may not easily align, because the strength of each molecular dipole is greater (Carlson and Illman, 1994). Thus polyvinyl chloride and polystyrene have dielectric strengths greater than polyethylene Barium titanate B at io 3, a crystalline ceramic, also has asymmetrical structure at room temperature (Ukpaka, 2017). The titanium ion is displaced slightly from the centre of the unit cell, causing the crystal to be tetragonal and permanently polarized in an alternating field, the titanium ion moves back and forth between its two allowable positions to assure that polarization is aligned with the field (Ukpaka, 2017 and David, 1999). The unique crystal structure and its rapid response to the applied field cause barium titanate and similar materials to have an extra ordinarily high dielectric constant. However, since polarization is highly anisotropic, the crystal must be properly aligned with respect to the applied field (Gustentin, 1988) editorcsp@bosaljournals.com

3 Fig. 3a: Polarization Mechanisms in Materials (Yaakor, 1996) Fig. 3b: The piezoelectric effect (Nigel, 1996) MATERIAL AND METHODS Capacitor construction parameters and characteristics All capacitors are formed with the same basic structure. Two parallel metal electrode plates are separated by a nonconductive material called the dielectric. When a voltage exists between these conductive parallel plates, an electric field is present in the dielectric. This field stores energy and produces mechanical forces between the plates. Capacitor parameters The amount of capacitance C for a parallel plate capacitor is determined by using equation (1) as stated below: 39 editorcsp@bosaljournals.com

4 The general formula shows that the larger the plate area, the larger the capacitance value; the smaller distance between the plates, the larger capacitance value; the larger the dielectric constant of the insulator (dielectric) material, the larger the capacitance. Practical Capacitance Fig. 4: Graph showing charging, a capacitor through a series resistance (parker, 2002) While capacitors have a sated capacitance, there are number of factors to consider in determining a capacitor usable capacitance. The dielectric material may cause a change in capacitance value depending on: Temperature, signal frequency, humidity, Dc/Ac/ voltages, age of capacitor, mechanical and piezoelectric effect. It is important that when selecting capacitor, these properties must be taken into consideration. Every capacitor is rated with a certain tolerance ground its nominal value, typically, the tolerance is coded using letters. The most common tolerance codes are; 20% = M, 10% = K, 5% = J, 2.5% = H, 2% = G and 1% = F The standard values used for manufacturing capacitors based on the E-series are like E6 and E12. This means capacitors have nominal capacitance such as the following: E6 series: 1, 1.5, 2.2, 3.3, 4.7 and 6.8 and their decimal multiples (10, 15, 20 etc). Fig. 5: A simple plate capacitor in which a dielectric of thickness d stores a charge that is proportional to the voltage applied between the conductor plates E12 series: 1, 1.2, 1.5, 1.8, 2.2, 2.7, 3.3, 3.9, 4.7, 5.6, 6.8, 8.2 and their decimal multiples. Capacitor properties An ideal capacitor has exactly the desired capacitance value and it is a perfect insulator. However, practical consideration must be taken into account for both the capacitance value and the amount of insulation provided by a given capacitor is described below as: the capacitor can store electric energy, (the capacitance value determines the amount of charge energy, at a given voltage), the capacitor can separate different DC voltage levels from each other, but also conducts the AC current and in general, the higher the frequency of the AC voltage the better the capacitor conducts the AC current. Fig. 6: A simple capacitor storing energy through conductor plates in a vacuum C = (1) Where, A is plate area, D is distance between plates and dielectric material constant dielectric constant x constant of vacuum. = (2) Where, is a plain number which expressed as: = 8.85 x F/M is Dielectric materials prosperities The response of material to an electric can be used to advantage even when no charge is transferred. The effects are described by the dielectric properties of the material. The dielectric material processes a large energy gap between the valance and the conduction bands, thus the material have a high electrical sensitivity. Two important applications for dielectric materials include electrical insulators and capacitors. Insulator are sued to prevent the transfer of charge in an electric circuit, these include and plastic covering on electrical wires and ceramics bills used in high voltage power lines. Capacitors are used to store electric charge. Other characteristics of dielectric include electrostriction, piezoelectricity and ferro electricity (Yan and Wong, 1993) editorcsp@bosaljournals.com

5 In electrical materials, the application of a field causes the formation and movement of dipoles. Diploes are atoms or group of atoms that have an unbalanced charge in an imposed field, the diploes become aligned in the material. Alignment of the dipoles causes polarization in an electric field. The ease within which polarization occur determines the behaviour of the dielectric material (Yan and Wong, 1903). Polarization in an electric field Fig. 7: Graph of Dielectric Constant against Area at Constant Capacitance of 1μf When an electric field is applied to a material, dipoles are induced within the atomic or molecular structure and become aligned with the direction of the field. In addition, any permanent dipoles already present in the material are aligned with the field. The material is therefore polarized. So polarization P(c/m 2 ) is calculated by the equation. P = Zqd (3) Where, z is the number of charge centres that are displaced per cubic metre, q is the electronic charge and d is the displacement between the positive and the negative ends of the dipole (Fig. 3). Electronic notarization Fig. 8: Graph of Dielectric Constant versus Area at Constant Capacitance of 2μf When an electric field is applied to an atom, the electronic arrangement is distorted, with electrons concentration on the nucleus near the positive end of the field. The atom acts as a temporary induced dipole. This effect is small and temporary. Ionic polarization When an ionically bonded material is placed in an electric field, the bonds between the ions are elastically deformed; the charge is minutely redistributed within the material. Depending on the direction of the field, cations and anions either move closer together or further apart. These temporally induced diploes provide polarization and may also change the overall dimension of the material. Fig. 9: Graph of Dielectric Constant against Area at Constant Capacities of 3μf. Molecular polarization Some materials contain natural dipoles. When a field is applied, the dipoles rotate to line up with the imposed field. When the field is removed, the dipoles may remain in alignment, causing permanent polarization. The permanent dipoles are present in asymmetrical molecules such as water and organic polymers, which are symmetrical. Certain ceramic crystals structures lack a centre of symmetry and also behave as dipoles. Space charge Fig. 10: Graph of Dielectric Constant against the Area at Constant Capacitance of 4μf Dipoles A charge may develop at interfaces between phases within a material, normally as a result of the presence of impurities. The charge moves on the surface when the material is placed in an electric field. This type of polarization is not an important factor in most dielectrics Factors affecting behaviour of materials 41 editorcsp@bosaljournals.com

6 Dielectric used for capacitor should exhibit a large degree polarization over a wide range of temperatures and frequencies. Several important factors influence the characteristics of capacitor upon dielectric constants which includes Electric resistivity Fig. 11: Graph of dielectric constant against the area at constant capacitance of 5μf. All dielectric that are effective have high electrical resistivity to prevent leakage or discharge of stored energy. Common dialectic have resistivity of Most of the dielectric materials for capacitor fall into one of the three groups, namely, liquids composed of polar molecules, polymers and certain ceramics. All possess permanent dipoles that move easily in an electric field yet still produce high dielectric constant (Semat and Jatx, 1958). Water Has high dielectric constant, is corrosive, relatively conductive and difficult to use in constructing capacitor devices. ganic oil and waxes are more effective Fig. 12: A bar chart of capacitance against the dielectric area with material (vacuum) These materials contain relatively long chain like molecules that serve as dipoles yet are easily aligned. Glassy polymers and crystalline materials These have lower dielectric constants and dielectric length than their amorphous counterparts. Frequency Dielectric materials are often used in alternating current circuits. The dipoles must therefore switch direction often at a high frequency. In order for the electronic device to perform satisfactorily, electric polarization occurs easily even at frequencies as high as Hz. Ironic polarization occurs readily up to Hz. Voltage Fig. 13: A bar chart of capacitance against the dielectric area with material (Rubber) Increasing the voltage of the applied field forces permanent dipoles into alignment, and further increase in voltage have little effect on polarization. However, high voltages may cause dielectric breakdown. Temperature When the temperature increases, permanent dipoles have a greater mobility, polarize more easily and give higher dielectric constant. Therefore, higher temperature permits the dielectric to breakdown and cause crystal structure to change to a less polar condition, which greatly reduces the polarization. Dielectric losses Fig. 14: A bar chart of capacitance against the dielectric area with material (polyvinyl chloride) Some energy is lost as a result of heat, when dielectric material is polarized in an alternating electrical field. The fraction of the energy lost during each reversal is the dielectric loss editorcsp@bosaljournals.com

7 Table 1: Capacitor construction and materials (Raymond and Jerry, 2000) Types of capacitor Capacitor shape and characteristics Mica (0.001in) Plate capacitors with good temperature stability, good for ratio Lead foil (0.0002in) frequency Mica sprayed Plate capacitors, same capacitance as other mica capacitors Silver coating Gcass-metal foil Plate capacitors, moisture, resistance same capacitance on mica capacitors Kraft paper (with wax or oil) foil or Rolled tubes, usually with several layers of paper between each set of metalized with lin conductors Plastic (Such as rolled tubes polyester) foil Ceramic-sprayed plate or tube type silver Electrolyte Al Al 2O5 liquid Ta TaO liquid Table 2: Functional Parameters of Dielectric Constants, Resistivity and Dielectric Strength for some Materials (Sheldon and Robert, 1982) Material Dielectric Constants (K) Resistivity (Ω ) Dielectric Strength (V/M) 60H H H Phenol-formal aldehyde Polyvinyl chloride Rubber Alumina Pyrex glass Vacuum Mica Piezoelectricity and electrostriction Polarization changes the dimension of the materials an effect called electrostriction. This might occur as a result of atoms acting as egg-shaped particles rather than sphere or bonds between iron changing in length or by distortion due to the orientation of the permanent dipoles in the materials (Haus and James, 1989). When a dimensional change is imposed on the dielectric, polarization occurs and a voltage or electric field is created. The dielectric materials that display this reversal are piezoelectric. There are two reactions that occur in piezoelectric, they are: Field produced by stress = = g (4) Strain produced by field = = d (5) Where, is the electric field (v/m), is the applied stress (Pa), - is the strain d is displacement and g are constants and the constant g is related to d through the modulus of elasticity E = (6) = (7) = (8) = (9) Where (a) Piezoelectric crystals have a charge difference due to permanent dipoles, (b) A compressive force reduces, the distance between charge centers, charges the polarization, and induces a voltage and (c) A voltage changes the distance between charge centers, causing a charge in dimensions. Charge/discharge behavior When a DC voltage is applied to a capacitor connected in series with a resistor, the capacitor begins to charge at a rate according to the applied voltage. The state of charge relative to its final value, the series resistance, and its own capacitance is a contributing factor to the system. The product of the resistance and the capacitance is referred to as the time constant. = RxC of the circuit, actually it is the time required to charge the capacitor by 63.2% of the difference between the initial value and the final value. Hence the value of charge plotted against time follows the curve shown in figure 4. During this time, the charging current follows the red curve as shown. Dielectric properties and capacitors Capacitor is an electrical devices used to store charge received from a circuit editorcsp@bosaljournals.com

8 plates and the design of the device. For simple parallel plate capacitor with only two plates, we have, C = (11) Where, A is the area of each plate, d is the distance between the plates, - is the permittivity of the material. The permittivity ( ) is the ability of the material to polarize and store a charge. The relative permittivity or dielectric constant (K) Fig. 15: A bar chart of capacitance against the dielectric area with material (pyrex glass) Is the ratio between the permittivity of the material and the permittivity of a vacuum, εo. K = ε/e_0 (12) units of charge and a total of 22 units. The permittivity εo of a vacuum is 8.85x10-12 F/m or 8.85x10-14F/cm. The dielectric constant K which depends on material, temperature, and frequency is related to polarization. P = (K-1) (13) Where, is the strength of the electric field (V/m) For capacitor containing a parallel conductor plates, the capacitance is Fig. 16: A bar chart of capacitance against the dielectric area with material (mica) Functions of capacitor To smoothen out fluctuation in the signal, to accumulate charge so as to prevent damage to the rest of the entire circuit, to store charge for later distribution, used to change the frequency of electrical signal as well as the following functions; Filtering remove or reduces unwanted AC voltages in application such as AM radio, cellular phones or IC switching noise application. Decoupling Enable sudden transfer of current (energy) while maintaining stable voltage levels. Coupling To block DC and passes AC components. Capacitors are designed so that the charge is stored in a polarized material between two conductors as illustrated below: The material between the conductor must easily polarized yet have a high electrical resistivity to prevent the charge from passing through one place to the other. Dielectric Constant The charge Q (coulombs) that can be stored by a capacitor is Q = CV (10) Where, V is the voltage across the plates of the capacitor and C is the capacitance Unit for capacitance are C/V or farad (f). The capacitance depends on both the materials between the C = (n-1) (14) Dielectric strength A small separation between the plates and high voltages causes the capacitor to breakdown and discharge. Dielectric strength is the maximum electric field that can be maintained between the plates. The dielectric strength therefore places an upper limit on C and Q (capacitance and charge). In order to construct smaller capacitors capable of storing large charges in an intense field, we must select materials with high dielectric strength and high dielectric constant. RESULTS AND DISCUSSION The results obtained from the investigation are presented in tables and figure (please mention numbers of tables and figures). We want to produce a parallel plate capacitor of capacitance 1 5 with various dielectric materials listed above with distance of separation to be kept constant in all our calculations to find out the area of the materials to be used respectively, with frequency at 10 6 Hz. The capacitance is given as C = K Therefore to find the A 12 /F/M), with a known constant of permittivity 8.85 No editorcsp@bosaljournals.com

9 Table 3: Computational parameters of dielectric area upon the influence of variable capacitance with constant distance Materials Dielectric constant (K) Formula/ calculation Capacitance (μf) Distance (m) 10 6 Hz Vacuum 1 A = cd ε o k Rubber 3.2 A = cd ε o k A b = A v 3 2 Poly vinyle chloride 3.4 A = cd ε o k A po = A v 3 4 Pyrex glass 4 A = cd ε o k A py = A v 4 Mica 7 A = cd ε o k A m = A v 7 Area (m 2 ) Table 4: Calculated values of dielectric area upon the variation of dielectric constant Area (m 2 ) Table 5: The calculated values of dielectric area upon the variation on the dielectric constant Area (m 2 ) Table 6: The calculated values of dielectric area upon the variation of dielectric constant Area (m 2 ) Table 7: The calculated values of dielectric area upon the variation of dielectric constant Area (m 2 ) Table 8: The calculated values of dielectric area upon the variation of dielectric constant Area (m 2 ) editorcsp@bosaljournals.com

10 Table 8: The calculated values of dielectric area upon the variation of dielectric constant Area (m 2 ) Table 9: The calculated values of dielectric area upon the variation of capacitance for vacuum Capacitance (μf) Area (m 2 ) Table 10: The calculated values of dielectric area upon the variation of capacitance for rubber Capacitance (μf) Area (m 2 ) Table 11: The calculated values of dielectric area upon the variation of capacitance fo polyvinyl chloride Capacitance (μf) Area (m 2 ) Table 12: The calculated values of dielectric area upon the variation of capacitance for pyrex glass. Capacitance (μf) Area (m 2 ) Table 13: The calculated values of dielectric area upon the variation of capacitance for mica Capacitance (μf) Area (m 2 ) Given Parameters, C = 1, d = 0.001m, Vacuum = K = 1 Using equation above to calculate the area of the materials with a given dialectic constant by materials is as calculated below. For vacuum: Vacuum K = 1, distance d = 0.001m, capacitance (c) = 1 Recalling the above equation to calculate the area, we have For pyrex glass K = 4 A p = = = ( ) = x m 2 A p = = = 28.25m 2 For mica, K = 7, A m = = = 16.14m 2 Where, C is capacitance, d is distance of separation between plates = Permitivity of free space, K = Relative dielectric constant A v = ( ) = = = ( ) x = x m 2 For Rubber K = 3.2 A b = = = ( ) = 35m 2 or A V/32.2 = 35m 2 For polyvinyl chloride, K = 3.4 A m = = = ( ) = x m 3 From the table above in table 2 and 3 of the properties of selected dielectric materials and the calculated figures from our experiment shows that the characteristics of a capacitor upon the influence of dielectric constant are as follows: 1. The larger the plate area, the larger the capacitance value. 2. The smaller the distance between the plate, the larger the capacitance value. 3. The larger the dielectric constant of the insulating (dielectric) material the larger the capacitance. A = = = 33.2m editorcsp@bosaljournals.com

11 As the capacitance value increases, the area increases while as the dielectric constant increases, the area decreases. The results of the calculated areas with capacitance ranging from 1 5 F of various materials and at frequency of 10 6 Hz with distance of separation of 0.001m as shown above: In figure 7 it is seen that the dielectric area decreases with increase in dielectric constant at a constant capacitances of 1. The variation in the dielectric area can be attributed to variation in the dielectric constant. In figure 8 it is seen that the dielectric area decreases with increase in the dielectric constant at a constant capacitance of 2. The variation in the dielectric area can be attributed to the variation in the dielectric constant. In figure 9 it is observed that the dielectric area decreases with increase in the dielectric constant at constant capacitance of Capacitance at 3. The variation in the dielectric area can be attributed to the variation in the dielectric constant. In figure 10 it is seen that the dielectric area decreases with increase in dielectric constant at constant capacitance of 4 the variation in the dielectric area can be attributed to the variation in the dielectric constant. In figure 11 it is observed that the dielectric area decreases with increase in dielectric constant at Constance capacitance of 5. This variation in the dielectric area can be attributed to the variation in the dielectric constant. Figure 12 shows that as the capacitance of a particular material (vacuum) increases, the dielectric area also increases. This increase in the dielectric area can be attributed to the increase in capacitance. Figure 13 shows that the capacitance of a particular material (Rubber) increases, the dielectric area also increases. This increase in the dielectric area can be attributed to the increase in capacitance. Figure 14 shows that the capacitance of a material (Polyvinyl chloride) increases with increase in dielectric area. This increase in the dielectric area can be attributed to the increase in capacitance. Figure 15 shows that as the capacitance of a material (pyrex glass) increases with increase in dielectric area. This increase in dielectric area can be attributed to the increase in capacitance. Figure 16 shows that as the capacitance of a material (mica) increases it brings about increase in the dielectric area. This increase in the dielectric area can be attributed to the increase in capacitance. CONCLUSIONS Carlson, G.T., Illman, B.L., The circular disk parallel plate capacitor American Journal of Physics 62, David, H., Robert, R.. Jearl, W Fundamentals of physics, Willy, New York, 6 th Edition, 59. David, J.J., Capacitors, capacitance and dielectrics, Department of physics, University of Idaho, P.O.Box , Moscow prepared with AAS, 106. Fzong, S.K., Lim, C.H., On the capacitances of a rolled capacitor, Physic Education, 37, Giore, T.T., Masters M.F., Miers, C., Determining dielectric constants using a paralled plate capacitor. American Journal of Physics 73(2) Gustentin. A.U., Dielectric state in a parallel plate capacitor. American Journal of Physics 56, Guy, A.G. et al., Introduction to material science, International students edition, Haus, H.A., James, R.M., Electromagnetic fields and Energy Engle wood clif, New Jessy prentice, 14. John J.M., Anthony, F.B., Experiment on the motion of a dielectric in parallel plate capacitor. American Journal of Physics 62, 931. John, B. et al., MIT physics II. Electricity and magnetism unpublished, 2 7. Nigel, P.C., Introductory DC/C electronics, 3 rd edition, Parker, G.W., Electric field outside a parallel plate capacitor. American Journal of Physics Raymond, S., Jerry, S.F., College Physics Sanders college publishing, New York, Robert, L.B., Introduction to circuit analysis, 6 th edition, Semat, H., Jatx, R Physics capacitance and dielectrics. Robert Katz publications, 157 (research paper in physics and Astronomy). Sheldon, H.R & Robert, T.F., Physics for scientists and Engineers, 5th Edition, Prentice Hall, Englewood, 45. Ukpaka, C.P., Material science (EEE 611) for PGD 1 Electrical/Electronic Engineering. Unpublished work Yaakor, K Measurement of dielectric constants of gases American Journal of Physics, 64, Yan, F.N., Wong, H.K., Force between the plates of a parallel plate capacitor. American Journal of Physics 61, From the experimental results and findings, it is evidently concluded that the evaluation on the characteristic of capacitor upon the influence of dielectric constant is that; as the capacitance increases, the area also increases while as the dielectric constant increases the area decreases. The larger plate area, the larger the capacitance value, the smaller the distance between plates, the larger the capacitance value and the larger the dielectric constant of the insulating (dielectric) material, the larger the capacitance. Finally, low dielectric constants are desirable for insulators, but high dielectric constants are required for capacitors. Visit us at: Submissions are accepted at: editorcsp@bosaljournals.com REFERENCES 47 editorcsp@bosaljournals.com