Capacitance and Dielectrics

In: Other Topics

Submitted By cooldave204
Words 520
Pages 3

Show the equations and calculations, and box your answer. Be sure to include the units.

NOTE: Any four questions from this HW will be graded, and the marks for this HW will be based on these only. (1, 2, 3, 12, 13, 18, 19, 21, 22, 29, 31, 32, 44)

1. A proton beam in an accelerator carries a current of 125 A. If the beam is incident on a target, how many protons strike the target in a period of 23.0 s?

2. A copper wire has a circular cross section with a radius of 1.25 mm. (a) If the wire carries a current of 3.70 A, find the drift speed of the electrons in this wire.

3. An aluminum wire having a cross-sectional area equal to 4.00 10–6 m2 carries a current of 5.00 A. The density of aluminum is 2.70 g/cm3. Assume each aluminum atom supplies one conduction electron per atom. Find the drift speed of the electrons in the wire.

12. A lightbulb has a resistance of 240 when operating with a potential difference of 120 V across it. What is the current in the lightbulb?

13. An electric heater carries a current of 13.5 A when operating at a voltage of 120 V. What is the resistance of the heater?

18. Aluminum and copper wires of equal length are found to have the same resistance. What is the ratio of their radii?

19. If the magnitude of the drift velocity of free electrons in a copper wire is 7.84 10–4 m/s, what is the electric field in the conductor?

21. If a certain silver wire has a resistance of 6.00 at 20.0°C, what resistance will it have at 34.0°C?

22. A certain lightbulb has a tungsten filament with a resistance of 19.0 when at 20.0°C and 140 when hot. Assume the resistivity of tungsten varies linearly with temperature even over the large temperature range involved here. Find the temperature of the hot filament.

29. A certain waffle iron is rated at 1.00 kW when connected…...

Similar Documents

Edm Wirecutting

...Identify the purpose of dielectric fluid in EDM List two common dielectric fluid Analyse the required properties of EDM tool List four common tool material for EDM Develop models for material removal rate in EDM Identify the machining characteristics in EDM Analyse the effect of process variables on surface roughness Analyse taper cut and over cut in EDM Identify different modules of EDM system Draw schematic representation of different electrical generators used in EDM Analyse working principle of RC type EDM generator 1. Introduction Electro Discharge Machining (EDM) is an electro-thermal non-traditional machining process, where electrical energy is used to generate electrical spark and material removal mainly occurs due to thermal energy of the spark. EDM is mainly used to machine difficult-to-machine materials and high strength temperature resistant alloys. EDM can be used to machine difficult geometries in small batches or even on job-shop basis. Work material to be machined by EDM has to be electrically conductive. 2. Process Fig. 1 shows schematically the basic working principle of EDM process. V (-ve) I Fig. 1 Schematic representation of the basic working principle of EDM process. Version 2 ME, IIT Kharagpur In EDM, a potential difference is applied between the tool and workpiece. Both the tool and the work material are to be conductors of electricity. The tool and the work material are immersed in a dielectric medium.......

Words: 3200 - Pages: 13

Voltage and Current Stress Induced Variations in Tin/Hfsixoy/Tin Mim Capacitors

...significant increase in leakage current was observed as a function of stress time. On the other hand, stress induced capacitance changes were observed due to change in quadratic and liner coefficients of permittivity nonlinearities. Stress-induced oxygen vacancy related defect formation believed to be the cause of this shift in permittivity. Ó 2012 Published by Elsevier Ltd. 16 17 18 19 20 21 22 Article history: Received 22 February 2011 Received in revised form 23 June 2012 Accepted 23 August 2012 Available online xxxx 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 Q3 1. Introduction Recently, Metal–Insulator–Metal (MIM) capacitors with high-k gate dielectrics are of significant interest for memory devices [1] and radio frequency (RF) applications to enhance the capacitance density [2]. It is because, these MIM capacitors show significant improvements compared to double poly linear capacitors because of reduction in series resistance. MIM capacitors also demonstrate lower parasitic capacitance due to reduced substrate coupling [3]. In addition, introduction of high-k dielectric materials enhances the capacitance density compared to low permittivity materials such as silicon nitride or oxide/nitride/oxide (ONO) dielectric stack thereby increasing the circuit density and reducing the cell size. Hafnium oxide-based dielectrics have been extensively studied for gate stacks in MOSFETs. Because of an interfacial layer between the......

Words: 3520 - Pages: 15

Electric Circuits

...Chapter 17 Electric Potential Units of Chapter 17 • Electric Potential Energy and Potential Difference •Relation between Electric Potential and Electric Field •Equipotential Lines and surfaces •The Electron Volt, a Unit of Energy •Electric Potential Due to Point Charges •Potential Due to Electric Dipole; Dipole Moment •Capacitance, Dielectrics and Storage of Electric Energy Electrostatic Potential Energy and Potential Difference The electrostatic force is conservative – potential energy can be defined as ΔPE= -W Change in electric potential energy is negative of work done by electric force: W =Fd=qEd Electric potential is defined as potential energy per unit charge: Unit of electric potential: the volt (V). 1 V = I J/C. Only changes in potential can be measured, Electrostatic Potential Energy and relation between Electric potential and Electric field Analogy between gravitational and electrical potential energy: Work is charge multiplied by potential: Work is also force multiplied by distance: If the field is not uniform, it can be calculated at multiple points: Solving problems Example 17-2: suppose an electron in a picture tube of television set is acclerated from rest through a potential difference of Vb-Va = Vba = + 50000V. (a) What is the change in electric potential energy of the electron? (b) What is the speed of the electron as a result of this acceleration? Equipotential Lines Electric potential can be represented with......

Words: 961 - Pages: 4

Physics Questions

...two charges as indicated. Which vector best represents the direction of the electric field at that point? a. Vector EA b. Vector EB c. Vector EC d. The electric field at that point is zero.   6. Inserting a dielectric material between two charged parallel conducting plates, originally separated by air and disconnected from a battery, will produce what effect on the capacitor? a. increase charge b. increase voltage c. increase capacitance d. decrease capacitance   7. Which of the following characteristics are held in common by both gravitational and electrostatic forces when dealing with either point masses or charges? a. inverse square distance law applies b. forces are conservative c. potential energy is a function of distance of separation d. all of the above choices are valid   8. Two point charges of values +3.4 and +6.6 microCoul are separated by 0.10 m. What is the electrical potential at the point midway between the two point charges? (k = 9 Ñ 10‹ N-m‚/C‚) a. +1.8 x 10ˆ6 V b. -0.9 x 10ˆ6 V c. +0.9 x 10ˆ6 V d. +3.6 x 10ˆ6 V   9. A 0.25 microFarad capacitor is connected to a 400 V battery. What potential energy is stored in the capacitor? a. 1.2 x 10^-12 J b. 1.0 x 10^-4 J c. 0.040 J d. 0.020 J   10. What is the equivalent capacitance of the combination shown? a. 29 microF b. 10 microF c. 40 microF d. 25 microF   11. A metallic conductor has a resistivity of 18 Ñ 10€ˆ ¦-m. What is the resistance of a piece that is 30 m long and has......

Words: 855 - Pages: 4


...normal to the surface. CAPACITANCE Parallel-Plate Capacitor: C = κ ∈0 C = capacitance [farads F] ∈0 = permittivity of free space 8.85 × 10-12 C2/N·m2 A = area of one plate [m2] d = separation between plates [m] Potential Energy of a Pair of Charges: [J, N·m or C·V] qq PE = q2V1 = k 1 2 r V1 is the electric potential due to q1 at a point P q2V1 is the work required to bring q2 from infinity to point P κ = the dielectric constant (1) Work and Potential: ∆U = U f − U i = −W U = −W∞ W = F ⋅ d = Fd cosθ W = q ∫ E ⋅ ds i f U = electric potential energy [J] W = work done on a particle by a field [J] W∞ = work done on a particle brought from infinity (zero potential) to its present location [J] F = is the force vector [N] d = is the distance vector over which the force is applied[m] F = is the force scalar [N] d = is the distance scalar [m] θ = is the angle between the force and distance vectors ds = differential displacement of the charge [m] V = volts [V] q = charge [C] Cylindrical Capacitor: L κ = dielectric constant (1) C = 2πκ ∈0 ln( b / a ) ∈0 = 8.85 × 10-12 C2/N·m2 L = length [m] b = radius of the outer conductor [m] C = capacitance [farads F] a = radius of the inner conductor [m] ∆V = V f − Vi = − V = − ∫ E ⋅ ds i f W q Spherical Capacitor: ab C = 4πκ ∈0 b−a C = capacitance [farads F] ∈0 = 8.85 × 10-12 C2/N·m2 b = radius, outer conductor [m] a = radius, inner conductor [m] κ = dielectric constant (1) Maximum......

Words: 5653 - Pages: 23

Business World

...addressed; E-Mail:; Tel.: +1-260-481-6356; Fax: +1-260-481-6281. Received: 18 December 2013; in revised form: 1 August 2014 / Accepted: 4 August 2014 / Published: 8 August 2014 Abstract: An innovative prototype sensor containing A36 carbon steel as a capacitor was explored to monitor early-stage corrosion. The sensor detected the changes of the surface- rather than the bulk- property and morphology of A36 during corrosion. Thus it was more sensitive than the conventional electrical resistance corrosion sensors. After being soaked in an aerated 0.2 M NaCl solution, the sensor’s normalized electrical resistance (R/R0) decreased continuously from 1.0 to 0.74 with the extent of corrosion. Meanwhile, the sensor’s normalized capacitance (C/C0) increased continuously from 1.0 to 1.46. X-ray diffraction result indicates that the iron rust on A36 had crystals of lepidocrocite and magnetite. Keywords: carbon steel; chloride; X-ray diffraction; rust; corrosion monitoring Materials 2014, 7 1. Introduction 5747 Corrosion is a destructive attack on a metal such as carbon steel, aluminum, zinc and copper by chemical or electrochemical reactions with its environment [1]. It is a spontaneous process. If corrosion is not monitored and correctly fixed, it could threaten public welfares and people’s lives [2]. Among various causes of corrosion, environmental factors are the most common ones because of ubiquitousness. Practically all environments are corrosive to some degree......

Words: 6878 - Pages: 28

Nerve Cells as Capacitors

...Nerve Cells Group Number: 2 Members: Eugene Clifford Sian Sweeney Matthew Kinsella Akin Goktas Introduction: In this report the mechanics and electrical theories of Nerve cells will be discussed. We will explore the way Nerve cells create and transmit electrical impulses and how a nerve cell membrane can be compared to a parallel plate capacitor. Topics such as Dielectrics, Capacitance and Permittivity will also be approached. In this problem we need to find the Electric Field intensity (E) within the membrane using surface charge density (σ). Find voltage (V) using E and the distance from plate to plate (d). Plot the relationship between σ and V on a graph and thus calculate Current (I) using this information and the area (A). For the purpose of this report the membrane faces will be referred to as “plate A” and “plate B”. Theory: A nerve cell membrane acts like a dielectric parallel plate capacitor, as it is water filled (dielectric material) and has two membrane faces (plate A & B). As seen in Figure 1 below. [pic] Figure 1: A dielectric parallel plate capacitor. [1] We portray charge lining up on the outer side of each face of the membrane just as on the plates of a capacitor [2]. As external forces cause the nerve cells to electrically transmit their messages, it is safe to assume that the impulses are triggered by a change in charge density, polarity, field intensity and /or other similar factors. In this problem......

Words: 1253 - Pages: 6

Cv and Transistors

...gate oxides. The MOS capacitance is characterized by its capacitance, Cox. It has two capacitors that are connected in series at the depletion layer. These two capacitors are depletion layer and oxide capacitors that is, Cdep and Coxrespectively. When the MOS-capacitor is supplied by AC voltage, the gap width increase and contracts with respect to the AC frequency (Huff, 2005, pg. 219). To maintain the reliability and the quality of MOS structures is a vital practice among the MOS capacitors. The C-V measurements are employed mostly to determine the details and quality of gate oxides. On the MOS capacitor, measurements are done at the absence of the drain and source. The test operations provide the process information and at the same time ensuring efficient devices. The interface charges and bulk charges are also part of the parameters that are determined. The capacitor voltage measurements are carried out using tools like the Keithley model. The Keithley model makes use of 4200-SCS apparatus. Parameters like capacitance, voltage and current are taken. Analysis of the obtained results can be done mathematically, graphically or by use of software. When software is used, a wide range of formulas are used so as to extract the basic C-V parameters. The MOS capacitor is a device fabricated by placing an oxide between a metal and a semiconductor. Poly-silicon can also be used in the place of the metal gate. The oxide serves the purpose of a dielectric material. The......

Words: 1575 - Pages: 7

Reflection Paper About Precious

... This page intentionally left blank Physical Constants Quantity Electron charge Electron mass Permittivity of free space Permeability of free space Velocity of light Value e = (1.602 177 33 ± 0.000 000 46) × 10−19 C m = (9.109 389 7 ± 0.000 005 4) × 10−31 kg �0 = 8.854 187 817 × 10−12 F/m µ0 = 4π10−7 H/m c = 2.997 924 58 × 108 m/s Dielectric Constant (�r� ) and Loss Tangent (� �� /� � ) Material Air Alcohol, ethyl Aluminum oxide Amber Bakelite Barium titanate Carbon dioxide Ferrite (NiZn) Germanium Glass Ice Mica Neoprene Nylon Paper Plexiglas Polyethylene Polypropylene Polystyrene Porcelain (dry process) Pyranol Pyrex glass Quartz (fused) Rubber Silica or SiO2 (fused) Silicon Snow Sodium chloride Soil (dry) Steatite Styrofoam Teflon Titanium dioxide Water (distilled) Water (sea) Water (dehydrated) Wood (dry) � r �� / � 1.0005 25 8.8 2.7 4.74 1200 1.001 12.4 16 4–7 4.2 5.4 6.6 3.5 3 3.45 2.26 2.25 2.56 6 4.4 4 3.8 2.5–3 3.8 11.8 3.3 5.9 2.8 5.8 1.03 2.1 100 80 1 1.5–4 0.1 0.000 6 0.002 0.022 0.013 0.000 25 0.002 0.05 0.000 6 0.011 0.02 0.008 0.03 0.000 2 0.000 3 0.000 05 0.014 0.000 5 0.000 6 0.000 75 0.002 0.000 75 0.5 0.000 1 0.05 0.003 0.000 1 0.000 3 0.001 5 0.04 4 0 0.01 Conductivity (� ) Material Silver Copper Gold Aluminum Tungsten Zinc Brass Nickel Iron Phosphor bronze Solder Carbon steel German silver Manganin Constantan Germanium Stainless steel , S/m 6.17 × 107 4.10 × 107 3.82 × 107 1.82 × 107 1.67 × 107 1.5 × 107 1.45 × 107......

Words: 177667 - Pages: 711

Engineering Thesis Sample (Credits to Owner)

...CMOS by Pankaj Kalra Doctor of Philosophy in Engineering – Electrical Engineering and Computer Sciences University of California, Berkeley Professor Tsu-Jae King Liu, Chair Transistor scaling has been the driving force for technology advancements in the semiconductor industry over the last few decades. In order to mitigate short channel effects, the gate-oxide thickness and source/drain junction depth have been scaled along with the gate length. Recently, however, gate-oxide thickness scaling has slowed, as evidenced by the fact that an equivalent oxide thickness (EOT) of ~1 nm has been used for the past 2-3 generations of CMOS technology. Although significant progress has been made in the development of high-permittivity (high-κ) gate-dielectric materials and metal gate technology in recent years, it will be difficult to scale EOT well below 1 nm. This makes junction-depth scaling even more pressing for continued transistor scaling. Furthermore, as the dimensions of MOSFETs are scaled down, the contact resistance of silicide-to-source/drain regions increasingly limits transistor performance. This is because the on-state resistance of a MOSFET drops with transistor scaling, whereas contact resistance increases with contact area scaling. Contact resistance increases exponentially 1 with Schottky barrier height (SBH) of the silicide-to-semiconductor contact. Thus, lower values of SBH will be needed in order to achieve substantial performance improvements with transistor......

Words: 18676 - Pages: 75

Electrical Properties

...(m2/V-s) ( -1-m-1) Si Ge 1.11 0.67 4 x 10-4 2.2 0.14 0.05 0.38 0.18 GaP GaAs InSb CdS ZnTe 2.25 1.42 0.17 2.40 2.26 1 x 10-6 2 x 104 - 0.03 0.85 7.7 0.03 0.03 0.015 0.04 0.07 0.01 Dielectric Property A dielectric material is an insulating material which can separate positive and negatively charged entities. Dielectric materials are used in capacitors to store the electrical energy. Capacitance Capacitance, C, is related to charge stored, Q, between two oppositely charged layers subjected to a voltage V. C = Q/V If two parallel plates of area, A, are separated by a distance l in vacuum, then C = o A/l. o, permittivity of vacuum = 8.85 x 10-12 F/m. If a dielectric material is present between the plates, C = A/l, is the permittivity of the dielectric medium. Relative permittivity constant. r = / o, also known as dielectric Capacitance and Polarization The orientation of a dipole along the applied electric field is called polarization (P). It causes charge density to increase over that of a vacuum due to the presence of the dielectric material so that D= o + P. is the electric field. D is surface charge density of a capacitor, also called dielectric displacement. Types of Polarization Four types of polarization: Electronic, Ionic, Orientation, and Space charge (interfacial). Electronic polarization is due to displacement of the centre of the electron cloud......

Words: 2132 - Pages: 9

Underground Cables

...differ from XLPE cables in terms of its physical and electrical properties? 4. What are the advantages of using XLPE cables instead of PILC cables? | The research problem is clearly stated.Research problem is in question form. | Objectives of the Study This study mainly aims to evaluate Cross Linked Polyethylene (XLPE) Insulated cables as substitute for Paper-Insulated Lead Covered cables for the efficiency of electrical transmission of underground distribution systems. The specific objectives of this study are: 1. To define the characteristics of an ideal underground transmission cables. 2. To identify the physical and electrical properties of the insulation materials of XLPE and PILC cables such as polymers, chemical compositions, dielectric losses, molecular structures, fibre structures, crystallinities, thermal expansion, cross linkings and degradations. 3. To compare the said electrical and physical properties of XLPE and PILC cables. 4. To analyse the comparison between XLPE and PILC cables. 5. To present the advantage of using XPLE insulated cables as an alternative for PILC cables. | Objectives are specific and attainable, realistic and time-bound.Can provide answers to the research problems. | Importance of the Study The lack of direct access to the transmission lines of underground distribution systems makes the maintenance of the system a challenge. Visual examinations cannot be made in case a failure or a problem in the system occurs. Also, fixing......

Words: 1876 - Pages: 8

The Capacitor Lab Report

...between two parallel plates and the capacitance, and the how the material of the plates impact the capacitance of the capacitor. In the first part, we are going to set vary the distance between two plates at interval of 0.5cm from 0.25cm to 4 cm to get sufficient data. In the second part of this experiment, we are going to change the material between two parallel plates in order to change the dielectric constant. Introduction: 1. We use a large parallel-plate capacitor in this experiment. It has two conductors and separated by an insulator. Because it stores capacitance, we call it capacitor. We connected one side of the capacitor with positive pole and the other side with negative pole. The amount of the charge on the capacitor is about the difference V and the magnitude of the capacitance on this capacitor: Q=CV 2. A simple parallel plate capacitor consists of two parallel conductors and is split by a distance. We also have a formula to descript the relationship between capacitance and some constants and variables. C= κεA/d Where κ is the dielectric constant, ε is the permittivity of free space (8.85*10^-12 C2/Nm2), and A is the cross sectional area of the parallel plates. Meanwhile, different sorts of material have different dielectric constant. With the increasing of distance between two plates, the capacitance is going to decrease. In addition, different material of the plates will have different capacitances. Material and Methods: 1.......

Words: 1551 - Pages: 7

Mr Bai

...Transistor. The device physics and electrical characteristics of the GAA SiNW TFET are investigated for better performance of gate control and low power consumption for the future scaling applications. Due to the high electric filed generated under the gate bias GAA SiNW TFET has high Ion and steep subthreshold swing. It is shown for the first time that subthreshold swing S is proportional to the diameter of the SiNW TFET and decreasing the diameter will lead to a better Ion /Ioff ratio. Device design and physics detailing the impact of drain and source engineering was discussed for SiNW TFET for lower off-state leakage current and a higher Ion with a steeper subthreshold swing S. Lastly, we have also investigated the effect of using high-k dielectric material and shorter gate length for SiNW for the future device applications. I. INTRODUCTION gate modulation gives a better Subthreshold swing which is smaller than 60 mV/decade and Lower Ioff Leakage Current of 10-14 A/um.[1],[2] Apart from Tunneling Field-Effect Transistor (TFET), Si Nanowires MOSFETs have been considered as the novel channel materials for the next-generation FET-type devices due to their novel material having promising device performance and novel transport characteristics. The outstanding performance of Si NW MOSFET is already shown in terms of high Ion /Ioff ratio and good subthreshold swings.[3],[4] We would integrate the SiNW to the channel of the TFET to achieve a better performance. The structure of......

Words: 5566 - Pages: 23

Losses in Transmission Lines

...ABSTRACT: - The transmission lines are considered to be impedance matching circuits designed to deliver rf power from the transmitter to the antenna, and maximum signal from the antenna to the receiver. During this signal transfer certain types of losses occurs e.g.-conductor losses, dielectric heating losses, radiation losses, insertion losses, power losses, and losses due to corona. The objective of this paper is to discuss all these losses. INTRODUCTION:- Before discussing about losses in transmission lines we have to know about transmission lines, their history, their theory, their properties and different types of transmission lines. A TRANSMISSION LINE is a device designed to guide electrical energy from one point to another. It is used, for example, to transfer the output rf energy of a transmitter to an antenna. This energy will not travel through normal electrical wire without great losses. Although the antenna can be connected directly to the transmitter, the antenna is usually located some distance away from the transmitter. On board ship, the transmitter is located inside a radio room and its associated antenna is mounted on a mast. A transmission line is used to connect the transmitter and the antenna. The transmission line has a single purpose for both the transmitter and the antenna. This purpose is to transfer the energy output of the transmitter to the antenna with the least possible......

Words: 3394 - Pages: 14