Resistance of a Wire
Background scientific knowledge Electricity Electricity is the movement of charge (electrons) around a circuit. The charge flows throw conductors which allow the electrons to pass through. An object which does not allow electrons to pass through is an insulator. Conductors intended to have resistance are called resistors (symbol ) Voltage- given the symbol V, measured in volts using a voltmeter Current- given the symbol I, measured in Amperes using an ammeter Metallic structure diagram Resistance Resistance is the ability to prevent or resist the flow of electrical current. Resistance occurs in an electrical circuit because of a collision between electrons and atoms, which slows the electrons down and converts some of their KE to heat energy. Resistance is measured in Ohms (?). Diagram Arrow shows direction of electron movement through the wire. Equation Factors which affect resistance Length of wire - this is being investigated Thickness of a wire - in a thin wire there are more possible paths for the electrons to pass through, therefore more electrons can flow through at one time, this increases the current which increases the resistance. Material of wire - wires of different densities will block more or less electrons Temperature - the vibration of warm molecules makes them more likely to collide with electrons, and resistance
Resistance of a Wire
Will changing the length and type of wire affect the resistance? What is my aim of this project: To set up an electric circuit to measure the resistance of the wire. What are my Variables: * Thickness of the wire * Length of the wire * Type of wire Equipment I plan to use: * Wires * Volt meter * Ammeter * Crocodile clips * Power pack * Ruler * Copper coil * Nichrome coil What is resistance? Resistance is measured in (OHMS). It is the hindrance to the flow of charge. Why did we get resistance? An electric current flows when electrons move through a conductor. The electrons that are moving can collide with the atoms of the conductor. This then means that it is more difficult for the current to flow, which causes resistance. On the other hand, electrons have a collision with atoms more often in a longer wire than they do in a short one, however, a thin wire has fewer electrons to carry the current than a thick wire. In a thin wire there is less space, but more resistance and in a long wire there is more space, yet less resistance. The flow of electrons: Hypothesis: Before I do my experiment I predict that the resistance in the wire will increase as the length of the wire increases. I also predict that if the resistance in the wire increases, then the thickness of the wire will decrease. My diagram of my circuit: For my first investigation task I will be
Resistance of a Wire
Resistance of a Wire Coursework Planing (Final) Independent variable: -Length of wire (cm) Dependent variable; -Dial voltage (4 volts) -Material of wire (Nickel chrome) -Width of wire (28 SWG) Aim: My aim is to see how the length of the wire affects the resistance. Prediction & Hypothesis: My prediction is that when the length of wire increases, the resistance will also increase. Same as when the length of the wire doubles, the resistance will also doubles because Resistance is caused when the electrons collide with the ions. Therefore when it is doubled, the electrons will collide with twice as many ions, so the resistance will also double. Introduction: Measuring equipments I have chosen a digital voltmeter and an ammeter as my measuring equipments because it shows the voltage and current in decimal points, so I know that my results can be more accurate. Range and intervals My length of wire will increase 10 cm every time and I will make 6 readings. I will repeat all my reading twice and get the average to make sure that they are the most accurate results that I can get. Results Plan The heading for my results table will be 'dial voltage', 'actual voltage', 'length of wire', 'current', and 'resistance'. To ensure a fair test I will make sure that the dependent variable will be the same through out the experiment. Safety I will assure that when I conduct
Resistance of a wire
INTRODUCTION - An electrical circuit was mounted using a power supply, an ammeter, a voltmeter and a resistor (wire). The voltage and current were worked out for different lengths of the wire using the ammeter (for the current) and the voltmeter (for the voltage). Using the voltage and current recordings, the resistances were calculated for each of the lengths. AIM - To investigate the correlation between the length and the resistance of a wire. DIAGRAM - PICTURE - HYPOTHESIS - I predict that the longer the wire, the greater the resistance. This is because the electrons have to move in a longer distance, making the opposition (resistance) of conductor to the current greater. RESULTS - Tables of results to show the resistance of the wire for different lengths. TRIAL 1 Length (cm) Voltage (V) Current (A) Resistance (?) 00 6,4 7,2 0,888888889 90 6,3 7,7 0,818181818 80 6,2 8,7 0,712643678 70 6,3 0,2 0,617647059 60 6,1 1,5 0,530434783 50 6,1 3,7 0,445255474 40 6,15 6,8 0,366071429 30 5,83 21,8 0,267431193 20 5,71 29,3 0,194880546 TRIAL 2 Length (cm) Voltage (V) Current (A) Resistance (?) 00 6,4 7,3 0,876712329 90 6,4 8,1 0,790123457 80 6,67 9 0,741111111 70 6,28 9,9 0,634343434 60 6,32 1,9 0,531092437 50 6,28 4,2 0,442253521 40 6,12 7,3 0,353757225 30 6,09 22,4 0,271875 20 5,9 32,9
Is Cloning Ethical?
Is Cloning Ethical? For the past few years the political and ethical argument for and against the process of cloning has been raging. So is cloning really unethical? Is it against human rights? Before we decide this we must first understand exactly what cloning is. Cloning can be done using a few different processes, which will be later mentioned. It is the creation of an embryo which is a genetically identical copy of another human (1). There are three main types of cloning. The first is known as Embryo Cloning. This is a technique, the same as the natural process of making identical twins or triplets, where cells are taken from a fertilised egg and encouraged to develop into twins or triplets with identical DNA (2). The second is known as Reproductive or Adult DNA Cloning. This method is used to produce an animal with identical DNA to an existing animal. DNA from an ovum is removed and is replaced by DNA from an adult animal cell. It is then implanted into the womb of a surrogate mother and develops into an animal. This kind of cloning is illegal in many countries as, based on studies performed on animals, it could cause genetic defects. It is considered by many to be unethical and dangerous, however Dr Severino Aninori claims to have used this procedure to initiate pregnancy (2) Biomedical Cloning, better known as Therapeutic cloning is the third process. In the
Narrative essay 1
Tanvi Dattani 0C Narrative Essay - Life changing fire The well sparkled in the moonlight. The bucket was heavy, but that compensated for the hard and tiring work I had done in the factory. The water was cool on my lips which was contradicted the heat in the shack. I closed my eyes, and heaved a sigh. Sheila once told me how she dreamed of one day going to Mumbai to go to study and making her parents proud. She always wondered if her parents were alive, they would be proud of her or not. This thought never left my mind. At the end of the bucket, the magical moment of freedom will be lost and back in the shack again. 'BOOOOOOMM!' the peace of the night was broken, pandemonium, pieces flying everywhere. The grandiose flames rose up, lay a beast within the earth, accompanied by an aura of smoke. Before I knew it the smoke encompassed me, like a tornado. I couldn't see, I couldn't breathe, I ran, ran far away, ran away from this lunacy. Running, running for my life but then I stopped. Sheila! My fear had vanished. I lost all sensation. I froze. I turned and ran towards the scorching conflagration. I ran towards the ferocious beast of fire and grime. Sheila, Sheila, Sheila. That was the only thought in my mind. The deafening noise of crackers, which was the only thing I could hear, seemed to roar in my ear. The fire stood like an unbreakable wall between Sheila and me. I
Outline and Evaluate Bowlby's Theory of Attachment
Outline and Evaluate Bowlby's Evolutionary Theory of Attachment Bowlby's theory is an evolutionary theory becuase he believes attachment is a behavioural system that has evolved because of its survival and reproductive value. Caregiving is adaptive because species have adapted over many years to enhanse survival of the offspring so they can later reproduce. Bowlby's theory is made up of many different ideas. According to Bowlby, children have an innate drive to become attached to a caregiver. This is similar to that of imprinting which is an innate readiness to develop a strong bond with the mother figure which takes place during the sensitive period. Since attachment is innate there is likely to be a limited window for development. This is said to be when a child is 3-6 months when a child is most sensitive to an attachemnt. After this stage attachment can become more difficult. The internal working model is a cluster of concepts about relationships and what to expect from others. In the short term it gives the child and insight into the caregivers behaviour. In the long term it acts as a template for future relationships as it generates expectations. This is similar to the continuity hypothesis and the idea that emotionally secure infants go on to be emotionally secure, trusting and confident adults. Social releases elicit caregiving such as smiling, crying, looking cute
Animal farm
Animal farm Through Animal Farm Orwell teaches us that no one in a position of power can remain true to their original cause, Discuss. George Orwell's classic novel Animal Farm was written to teach people a very important lesson. That few people who have an opportunity to take control and gain power will stay true to their original aims and beliefs. Animal Farm tells a tragic story that aims to prove that human nature and diversity prevent people from being equal and happy. The story takes place on Manor Farm, where animals are overworked and underfed by their drunken human master Mr Jones. However, the animals on this farm catch the wind of rebellion and decide to rise up against their masters. This is all sparked by a dream that a boar named Old Major had about a unique place where animals ruled themselves and where everyone is happy and equal. When Old Major died, the animals acted quickly and were able to overthrow the humans. Their new idea of government was known as animalism, and it was agreed upon that each creature would work according to their capability and respect the needs of others. Seven commandments were agreed upon and all animals swore faithfully to uphold these laws. The laws were: no animal shall drink alcohol, wear clothes, sleep in a bed, kill another animal, those who go upon four legs or have wings are friends and those that walk on two legs are
Animal Farm Essay
Animal Farm Essay 'Animal Farm,' a novel by George Orwell, has a theme based around power; how it is abused and how it's used in a good way. 'Animal Farm' also explores how it is transferred between characters as the story progresses. It is also fair to say that every event that takes place on 'Animal Farm' has a political significance which mirror the events which took place in the Russian Revolution. The characters in the novel represent famous political figures from history. I think that George Orwell wrote 'Animal Farm' because he wanted to make people actually think about what the novel and the characters contained in it represent. Power on 'Animal Farm' ends up being totally abused - I think that George Orwell's theory is that when one person has absolute power, it corrupts completely, and that it will never work. At the beginning of 'Animal Farm' we see how Mr Jones is at the top of the power 'hierarchy;' he has the most power, although it's more of an authority that Jones has over the animals compared to him having power. In a way, Jones having all the authority over the farm was a good thing, as all the animals knew where they stood, however, the normal farm animals, who represent the citizens of Russia, wanted more authority and power over the ruling of the farm; the country in Russia's case. Fed up with slaving for Jones and getting nothing except the bare
Animal Testing
Is Animal Testing/Research Necessary for Advancing in Medicine? Introduction: Animal testing involves using non-human animals for scientific procedures. Animal research can be used for a number of things such as developing new drugs to improve health, learning about animals and the human body, aiding scientific advances and ensuring other products do not harm humans. Vaccinations against diseases like polio, rabies, measles, mumps and rubella were developed because they were tested on animals. Also the development of open-heart surgery and organ transplants depended on operations done on animals. In 2006 approximately two million animals were used in procedures. Animals that are normally used in tests and experiments include: rats, mice, rabbits, monkeys, guinea-pigs, cats, dogs, fish, birds, pigs, horse, sheep and hamsters. This pie chart shows the types of animals used in procedures. A large proportion of experiments are conducted on mice. (1) Those who are extremely against animal testing (animal rights activists) would refer to it as 'vivisection'. This means the 'cutting up of animals'. They refer to animal testing being morally wrong and cruel. However this is just one view, others are not so against animal testing. Others may believe that animal testing is necessary for some purposes for example medicinal purposes yet not for beauty products. Methods of
