...Lab 2 Problem 4: Resistors and Light Bulbs Ruth Nyagitari March 8, 2016 Physics 1202W, Professor: Thomas Walsh, TA: Joshua Hitbrand Abstract In order to determine the similarities and differences of the electrical properties of light bulbs and resistors the relationship between the voltage across a light bulb and the current through the light bulb was compared to a resistor. A power source was used as a source of potential difference. The change in resistance was observed as well as change in the applied voltage. The voltage versus the current was analyzed using ohms law it was predicted that if voltage across a resistor increases the current through the resistor will increase as well. Introduction While debating about the role of electric circuits in biological systems it was argued that a light bulb may not be a good model for biological electrical energy transfer. A light bulb is easy to observe difference in energy transfer rates by observing the change in brightness. However in order to give light it’s raised to temperature higher than biological systems. Instead a resistor was suggested to be a better model for biological systems because its transfers energy out of the electric circuit without extreme behavior of a bulb. To determine the similarities and difference between use of bulbs and resistors a graph is drawn depicting the relationship between the voltage across a light bulb to the current through the light bulb and then compared to a resistor. In the experiment...
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...The Combination of Cells and Resistors in a Circuit Name: Emmanuel BALOME ID Number: 20140385 Group Number: A2 Lab Partners: * Christopher BAGME * Leandra BANIYAMAI * Amex BATEME * Kingston BOB * Natalie BROWN Abstract Batteries and resistors can be connected in both series and parallel circuits where the current and voltage running through them can be altered. Batteries connected in series give off large amounts of electromotive force while the reverse happens when connected in parallel. Resistors connected in series are added individually while an inverse summation results while connected in parallel. These are the effects that will be closely studied in this report. Introduction All electronic devices and setups require some complex form of wiring for proper functionality. To do so electricians have to understand the effects of electricity and how it can be managed. Batteries or more preferably ‘dry cells’ produce electromotive forces that create electric fields that help drive electrons around circuits. There are two common circuit arrangements; one is called the series circuit while the other is called the parallel circuit. Components in series circuits are connected one after another where the whole current flows through each component, while components in parallel circuits are arranged in a way that the current breaks up so that a fraction of it flows through a component. These type of wirings are found in common housing circuits but...
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...potential difference between its terminals is called the ELECTROMOTIVE FORCE (emf) of the battery. * The unit for emf is the same as the unit for potential difference, the VOLT. * RESISTANCE * The resistance of wire or other object is a measure of the potential difference that must be impressed across the object to cause a current of one ampere to flow through it. * R = V/I * The unit of resistance is OHMS (Ω), 1Ω = 1V/A. * OHM’s LAW * Ohm’s Law originally contained two parts. * The defining equation for resistance, V = IR, also stated the R is a constant independent of V and I. * The relation V = IR can be applied to any resistor, where V is the potential difference between the two ends of the resistor, I is the current through the resistor, and R is the resistance of the resistor under those conditions. * GEORG SIMON OHM * 1787-1854 * A high school teacher in Cologne and later a professor at Munich * Formulated the concept of resistance and discovered the proportionalities expressed in * MEASUREMENT OF RESISTANCE BY AMMETER AND VOLTMETER * A series circuit consisting of the resistance to be measured, an ammeter, and a battery is used. * The current is measured by the ammeter. * The potential difference...
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...The objective of this lab is to learn to use resistors and how they are used in series and in parallel. A resistor is an electrical component that limits or regulates the flow of electrical current in an electronic circuit. Electrical current is the rate of charge flowing past a given point in an electric circuit, measured in coulombs/seconds known as amperes. We are using the Ohm’s law (V=IR, V is voltage, I is the current and R is the resistor) to calculate the current of the resistors and the voltage of the resistors. There are different kinds of currents and one that we are going to be using in this lab is direct current. Direct current is when the charge flows in only one direction around the circuit and in a alternating circuit is when the direction of the charge flows changes from moment to moment. When resistors are in series they look like this . When a resistor is in series and we are trying to find the resistance equivalent we use this formula R eq=R1+ R2 . A parallel resistor is when two or more resistors are connected in parallel and it looks like this.... To find the resistance equivalent in a parallel resistor is different than the series in parallel you use this formula, 1Req=1R1+1R2 also it can be simplify to this Req=R1R2R1+R2. All the words we are using in this lab we have learn in class and has been taught to us which will help us more and to understand better the lab. Resistor could be use in many different products we use in our daily lives like in...
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...is easier said than done. Also if you’re the kind of person that fights for their relationship no matter what, then the end result would be priceless, having two of the men you shared part of yourself with become friends end the end “ Why Can’t We All Just Get Alone” spoken by Rodney King. Project Description The two stage common emitter amplifier circuit commonly is called voltage divider biasing. This type of biasing arrangement uses ten resistors including one swamping resistor as a potential divider network and is commonly used in the design of a bipolar transistor amplifier circuits. This method of biasing the transistors greatly voltage divider network reduces the effects of varying Beta by holding the base bias at a constant steady voltage level for the best stability. The base voltage is determined by the potential divider network formed by the current flowing through the resistors. The total resistance will be equal to the given current as VCC and RT. The voltage level generated at the junction of the resistors...
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...procedures is to use the dc offset to make sure no dc voltage is in Vin. This is because the input offset voltage is not zero or another word, the supplied voltage work together with AC and DC. Hence, the dc input voltage will be integrated and the output voltage starts to drift. Part 4.6 An op-amp without a feedback resistance is original a difference amplifier. The difference op-amp produces the algebraic difference between the two input signals. Few cases can be done in the difference op-amp. Example like the two input voltage have the same magnitude and the output voltage will be zero which will be the most common. There are no amplification take places when all the external resistors value is the same. Hence, the amplification of the difference op-amp is depends on the ratio of the resistor value. V+ V- B A The output voltage equation can be derived using super position theorem and voltage...
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...ELECTRICAL SYMBOLS – K Hinds Circuit symbols are used in circuit diagrams which show how a circuit is connected together. The actual layout of the components is usually quite different from the circuit diagram. To build a circuit you need a different diagram showing the layout of the parts on stripboard or printed circuit board. Wires and connections Component Circuit Symbol Wire Function of Component To pass current very easily from one part of a circuit to another. A 'blob' should be drawn where wires are connected (joined), but it is sometimes omitted. Wires connected at 'crossroads' should be staggered slightly to form two Tjunctions, as shown on the right. In complex diagrams it is often necessary to draw wires crossing even though they are not connected. I prefer the 'bridge' symbol shown on the right because the simple crossing on the left may be misread as a join where you have forgotten to add a 'blob'! Wires joined Wires not joined Power Supplies Component Cell Circuit Symbol Function of Component Supplies electrical energy. The larger terminal (on the left) is positive (+). A single cell is often called a battery, but strictly a battery is two or more cells joined together. Battery DC supply AC supply Fuse Transformer Earth (Ground) Supplies electrical energy. A battery is more than one cell. The larger terminal (on the left) is positive (+). Supplies electrical energy. DC = Direct Current, always flowing in one direction...
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...LDRs and Thermistors LDRs are light dependent resistors that are often used in circuits where it is necessary to detect the presence or the level of light. A light dependent resistor is a component that is sensitive to light; therefore when light falls upon it the resistance changes. The value of resistance of the LDR is subject to change over many orders of magnitude when the value of the resistance falls as the level of light increases. It is fairly simple to understand the basics of how an LDR works, first of all it is necessary to understand that an electric current consists of the movement of electrons within a material. Good conductors have a large number of free electrons that can drift in a given direction under the action of a potential difference. However insulators with a high resistance have very few free electrons therefore it is hard to make them move and hence a current to flow. An LDR is made of any semiconductor material with a high resistance. Consequently it has a high resistance because there are very few electrons that are free and able to move; as the vast majority of the electrons are locked into the crystal lattice and unable to move. Therefore in this state there is a high LDR resistance. As light falls on the semiconductor, the light photons are absorbed by the lattice and some of the energy is transferred to the electrons. This gives some of them sufficient energy to break free from the crystal lattice so that they can then conduct electricity...
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...Keypad System By: Julian Garcia and Christian White ET2640 Microcontrollers and Microprocessors Mr. Wysuph List of Components I. Breadboard II. 8051 microcontroller III. 4x4 Hex keypad IV. 7 – segment display V. Keil program software VI. 5 volt power supply VII. 330 ohm resistor pack VIII. 1 resistor (8.2K ohm) Progress Update Although our circuit is not built, we have made progress. We have to order a part in order for the project to work. We have to order the 4x4 hex keypad. Once the keypad arrives, we can wire it to our breadboard or the trainer. In order for this project to work, we must make sure that our circuit chips have power (VCC) and are grounded. After that is done, we will take our 33pF capacitors and connect them to our 11.0592MHz oscillator, which is connected to XTAL1 and XTAL2 on the 8051 trainer. We will then tie R1 – R4 and C1 – C4 on our hex keypad to ports 1.0 through 1.7 together on the 8051. Ports 0.0 – 0.7 on the 8051 will have a 330 ohm resistor pack connected to the 7 segment display. We will then have our 10uF capacitor tied together with the 8.2k ohm resistor, which should be connected to our reset. Test Plan To troubleshoot the circuit, we first must know how it is supposed to work. If the keypad is not working, we must check all connections and we can use a logic probe to see if we are getting an output at certain pins. We can also use the logic probe if our 7 – segment display is not lighting up or not...
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...more resistors are added in parallel to a circuit, the equivalent resistance of the circuit ____________ (increases, decreases) and the total current of the circuit ____________ (increases, decreases). 2. Three identical light bulbs are connected to a battery as shown below. P, Q, X, Y and Z represent locations along the circuit. Which one of the following statements is true? a. The current at Y is greater than the current at Q. b. The current at Y is greater than the current at P. c. The current at Y is greater than the current at Z. d. The current at P is greater than the current at Q. e. The current at Q is greater than the current at P. f. The current is the same at all locations. 3. Three identical light bulbs are connected to a battery as shown below. P, Q, X, Y and Z represent locations along the circuit. At which location(s), if any, will the current be ... a. ... the same as at X? b. ... the same as at Q? c. ... the same as at Y? d. ... less than at Q? e. ... less than at P? f. ... twice that at Z? g. ... three times that at Y? 4. Which adjustments could be made to the circuit below that would decrease the current in the battery? List all that apply. a. Increase the resistance of bulb X. b. Decrease the resistance of bulb X. c. Increase the resistance of bulb Z. d. Decrease the resistance of bulb Z. e. Increase the voltage of the battery. f. Decrease the voltage of the battery. g. Remove bulb Y. 5. A 12-V battery , a 12-ohm resistor and a...
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...A Pragmatic Introduction to the Art of Electrical Engineering Paul H. Dietz Version 1.0 - ©1998 Paul Henry Dietz - All rights reserved. A Pragmatic Introduction to the Art of Electrical Engineering i L ICENSE Rights and Obligations vii How it Works vii A Disclaimer viii C REDITS How Did We Get Here? ix A Book is Born ix And I Want to Thank All the Little People... x P ROLOGUE Electrical Engineering for Fun and Profit xi Cold Sandwiches, again? xi Electrical Engineering as Programming and Interfacing xii The Basic Stamp 2 xiii About This Book xiv C HAPTER 1 Getting Started with the BASIC Stamp 21 The Problem 1 What You Need to Know 1 What is a BASIC Stamp 2? 2 How Do I Wire it Up? 2 How Do I Get to the Software? 5 A First Example Program 5 A Second Example Program 6 ii A Pragmatic Introduction to the Art of Electrical Engineering C HAPTER 2 Lights and Switches 8 The Problem 8 What You Need to Know 8 What is Voltage? 9 What is Current? 10 What is an LED? 12 How Do I Interface a Switch? 16 What is a Seven Segment Display? 18 Where Do We Go Next? 20 C HAPTER 3 Maybe 21 The Problem 21 What You Need to Know 22 What is a Voltage Divider? 22 How Do I Solve More Complex Resistive Circuits? 24 Are There Any Tricks That Can Make This Easier? 27 What is an Independent Source and What is Superposition? 30 What is a Digital to Analog Convertor? 32 What’s Next? 33 C HAPTER 4 Guess the Number 34 The...
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...PROJECT PROPOSAL IN ELLECT 03 60W MosFet Audio Amplifier And Curiously Low Noise Amplifier SUMITTED BY: IGLESIAS, GINO GORRICETA, JOSEPH GOC-ONG, JOSE LABSOG, JERRYL JOHN JUSOS, CLYDE 60W MosFet Audio Amplifier High Quality, powerful unit: 90W into 4 Ohm load Also suited as guitar or bass amplifier CIRCUIT DIAGRAM: R1______________47K 1/4W Resistor R2_______________4K7 1/4W Resistor R3______________22K 1/4W Resistor R4_______________1K 1/4W Resistor R5,R12,R13_____330R 1/4W Resistors R6_______________1K5 1/4W Resistor R7______________15K 1/4W Resistor R8______________33K 1/4W Resistor R9_____________150K 1/4W Resistor R10____________500R 1/2W Trimmer Cermet R11_____________39R 1/4W Resistor R14,R15___________R33 2.5W Resistors R16_____________10R 2.5W Resistor R17_______________R22 5W Resistor (wirewound) C1_____________470nF 63V Polyester Capacitor C2_____________470pF 63V Polystyrene or ceramic Capacitor C3______________47µF 63V Electrolytic Capacitor C4,C8,C9,C11___100nF 63V Polyester Capacitors C5______________10pF 63V Polystyrene or ceramic Capacitor C6_______________1µF 63V Polyester Capacitor ...
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...Name: Date: 13.3 Ohm's Law A German physicist, Georg S. Ohm, developed this mathematical relationship, which is present in most circuits. This relationship is known as Ohm's law. This relationship states that if the voltage (energy) in a circuit increases, so does the current (flow of charges). If the resistance increases, the current flow decreases. Voltage (volts) Current (amps) = --------------------------------------------Resistance (ohms, ) To work through this skill sheet, you will need the symbols used to depict circuits in diagrams. The symbols that are most commonly used for circuit diagrams are provided to the right. If a circuit contains more than one battery, the total voltage is the sum of the individual voltages. A circuit containing two 6 V batteries has a total voltage of 12 V. [Note: The batteries must be connected positive to negative for the voltages to add.] If a toaster produces 12 ohms of resistance in a 120-volt circuit, what is the amount of current in the circuit? Given The resistance (R) is 12 ohms. The voltage (V) is 120 volts. Looking for The amount of current (I) in the circuit. Relationships V I = -R Solution 120 volts I = V = --------------------- = 10 amps -R 12 ohms The current in the toaster circuit is 10 amps. If a problem asks you to calculate the voltage or resistance, you must rearrange the equation I=V/R to solve for V or R. All three forms of the equation are listed below. V V II = V-V IR R R R I In this section...
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...Construction and Operation In this method, resistors are temporarily placed in series with the motor windings during startup. A voltage drop is created across the series resistors during startup, resulting in a lower starting voltage applied to the motor’s terminals. Once the motor has accelerated to normal operational speeds, the resistors may be “removed” and the motor allowed to operate under normal conditions. At startup, the start contacts are closed, forcing the starting currents to flow through the series resistors. Once the motor has been allowed sufficient time to accelerate, the run contacts are closed, thus bypassing the resistors. A timer may be utilized within the control circuit to allow the motor to transition from “start” to “run” operation automatically. Applications 1. Usually on low voltage (less than 600 v). 2. Where current reduction requirements are low, or where load torque during acceleration is minimal. 3. Not often used with large motors because of the high heat loss in the resistors. 4. May be used for full acceleration or for system voltage recovery. Advantages 1. reduced heat loss 2. greater ease of start 3. (If correctly designed and constructed), this method will cause the motor to accelerate the load to almost full speed with the resistors in circuit before they are bridged out. Disadvantages 1. The resistors must be cooled in between starts because of the heat build up in the resistors during start, and their temperature dependant...
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...Charge the capacitor by closing the switch on the left. Sketch the graphs of Voltage vs. Time for the resistor and the capacitor below. b. What happens to the current through the circuit as time goes on? It slows down from .40 Amps to .00 Amps as time goes on and then stays at 0.00 Amps. c. What happens to the amount of charge on the capacitor as time goes on? It hits a peak and stays the same. d. Now discharge the capacitor by opening the switch on the left and closing the switch on the right. Sketch the graphs of Voltage vs. Time for the resistor and the capacitor below. e. What happens to the current through the circuit as time goes on? It starts at .40 Amps and decreases to .00 Amps. f. What happens to the amount of charge on the capacitor as time goes on? It decreases to 0 and then stays g. Predict the changes to the graphs if the amount of resistance increases by drawing additional lines on your graphs above. Explain the reasons for your predictions. If the resistance increases than it should take longer for the current to reach zero. It will also take longer for the voltage of the resistor and capacitor to get back to zero in both the charge and discharge graphs. h. Right click on the resistor and increase the resistance. Use another color to show the results on your charging and discharging graphs...
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