Electromagnetic Induction
AIM To determine some conditions under which a magnetic effect will produce an electric effect; and to study the factors which affect the induction of a current in a conductor. BACKGROUND INFORMATION Experiments with magnetic fields show that an electric current in a wire has a magnetic field associated with it. If an electric effect can produce a magnetic effect, maybe the reverse may also be true, i.e. a magnetic effect may produce an electric current. APPARATUS * Ballistic galvanometer * Horseshoe magnet * Bar magnets * Leads * Wired metal rod * Induction coils * 60 microamp galvanometer METHOD . The coil was connected to a Microammeter. The N pole of the magnet was inserted into the solenoid and a description was recorded. 2. The magnet was held stationary in the solenoid. A description of the results was recorded. 3. The N pole was withdrawn from the solenoid and a description was recorded. 4. Steps 1-3 were repeated with different speeds. 5. Steps 1-4 were repeated with a magnet of a different strength. 6. All observations were recorded. RESULTS Motion of magnet Galvanometer needle North pole in Remained at zero Stationary Momentarily moved to right hand side North pole out Momentarily moved to left hand side North pole in Magnitude of induced current (microamperes) Stationary 0 Slow 0.2 Fast 0.6 Strength of magnet Magnitude of
The Acceleration of a Freely Falling Body
The Acceleration of a Freely Falling Body To study the motion of a freely falling body, an object is allowed to fall and its position after successive equal time intervals is recorded on wax-coated paper by means of electric sparks. From these data, graphs of distance vs. time and velocity vs. time are plotted. The acceleration due to gravity is found by determining the slope of the velocity vs. time graph. Theory In one dimension, an object's average velocity over an interval is the quotient of the distance it travels and the time required to travel that distance: (1) where and . The instantaneous velocity at a point is defined as the limit of this ratio as the time interval is made vanishingly small: (2) Hence, the velocity is given by the slope of the tangent to the distance vs. time curve. If the velocity were constant the slope would be constant, and the curve would be a straight line. This is evidently not the case for a freely falling body, since it is at rest initially but has nonzero velocities at later times. When the velocity of a body varies, the motion is said to be accelerated. The average acceleration over an interval is the quotient of the change of the instantaneous velocity and the time required for that change: where . The instantaneous acceleration is defined analogously to the instantaneous velocity: (3) If a body moves in a straight line
The aim of this investigation is to establish a connection between the factors and the output.
EMF Investigation Planning Aim and hypotheses According to Fleming's Rule, electricity is generated when movement occurs in the magnetic field. Alternatively, switching direction of the magnetic field also works. Alternating current is a good way of alternating the field direction. The electricity generated, of in the other words, the electromotive force, is measured in volts. By varying different parts of the apparatus, the EMF output could also vary. The aim of this investigation is to establish a connection between the factors and the output. Possible factors that could be altered in a general apparatus are: * Frequency of field alternation * No of coil of wire in the magnetic field * Strength of magnetic field, varied by * - size of electromagnet * - current used to establish and maintain the magnetism of the electromagnet * - no of coil used to magnetize the electromagnet * Moving the wire in the magnetic field A preliminary experiment, with the same apparatus used, is done earlier on and some useful information was acquired from it. As it was mentioned that alter the direction of the field generates electricity, and it was found out in the preliminary experiment that the more frequent that the field is altered, the quicker would electricity be generated, so by looking at different frequency, perhaps a pattern indicating the relation. In an experiment
Determination of Force Constant k from Spring-mass System
Title: Determination of Force Constant k from Spring-mass System Objective: To measure the force constant k from a vertical spring-mass system Theory: A horizontal or vertical mass-spring system can perform simple harmonic motion. Let period be T, mass be m and force constant be k. Consider a vertical spring-mass system. Take downward as positive. Displacement of mass: x Static extension: e When it is in equilibrium: By Hook's law, With an arbitrary downward displacement x, the spring is stretched and there is a spring force pointing upward. The mass then accelerate upward. When the mass passes through the equilibrium position, there is no net force but with inertia, the mass goes upward and the spring is compressed then induce a downward spring force. The mass then accelerate downward and passes through the equilibrium position again. This process repeats itself if there is no other external forces. We can see that the displacement from equilibrium position always oppose its acceleration which means this is simple harmonic motion(SHM). We can see that the mass will accelerate upward. As the mass is moving in SHM, (by SHM equation) So by measuring the oscillation period and the mass of mass, we can calculate the spring constant (or say the force constant). Apparatus: Slotted mass (10g, 20g, and 50g), hanger, spring, retort stand and clamp, stop watch.
Investagate the strength of an electromagnet
Aim The aim of the experiment is to investagate the strength of an electromagnet Introduction An electromagnet is a coil of wire wound on a soft iron core. Unlike refrigerator or bar magnets, electromagnets use electricity to generate a magnetic field. In addition, electromagnets give us the ability to turn the magnetic field on or off as we need. To make an electromagnet, you need electricity (usually supplied by a battery or a larger power source) and something for that electricity to flow through (wire coils, for example). Sometimes, the wire of an electromagnet is wound around a metal rod to increase the magnetic field strength. The electromagnet was discovered in 1820 by a man named Oersted.He accidentally discovered that a wire with electricity running though it made a compass deflect from the Earth's North Pole. In fact, the compass needle was perpendicular to the direction of the electric flow. That meant that the electricity flowing in the wire generated its own magnetic field that was disrupting the nearby compass! Since then, scientists have found many ways to use electricity to generate magnetic fields and for magnets to make electricity. Oersted observed what we now call the "right-hand rule." The right-hand rule states that if you make a fist, when you point your right-hand thumb in the direction of electric flow, the rest of your fingers curl in the direction
New Technological Advances in Wing Design
New Technological Advances in Wing Design Aeronautics is at the forefront of engineering, with new technology and fresh ideas being developed constantly. The main concern at the moment regarding aircraft design is the environmental effects it has, specifically, how much fuel an aeroplane burns. There have been many innovations in this field. Here, I will talk about a few of the fairly new concepts linked to wing design that I have come across. Morphing Winglets As shown above, the winglets of a plane reduce drag and increase handling and manoeuvrability. By reducing drag, they can increase fuel efficiency from 3-5%. However, as the angle of flight, the speed, and altitude changes, so does the wingl1et efficiency. Normally, the winglet is at an angle of 25o to the vertical (the cant angle), which creates maximum efficiency. Presently, Boeing and Airbus are designing the winglets so that the cant angle is able to change during flight. It will be altered for take-off, climb, cruise and landing approach. This way, drag will be a minimum, and the fuel efficiency will be constantly at 5%. Also, because there will be less fuel needed to fuel the engine, the engine will make less noise, meaning the landing will be quieter. The winglets will also be able to be flattened, which will create a greater lift force on the plane. Boeing has patented the winglet design, which involves
Electromagnetic Radiation.
I INTRODUCTION Electromagnetic Radiation, waves produced by the oscillation or acceleration of an electric charge. Electromagnetic waves have both electric and magnetic components. Electromagnetic radiation can be arranged in a spectrum that extends from waves of extremely high frequency and short wavelength to extremely low frequency and long wavelength. Visible light is only a small part of the electromagnetic spectrum. In order of decreasing frequency, the electromagnetic spectrum consists of gamma rays, hard and soft X-rays, ultraviolet radiation, visible light, infrared radiation, microwaves, and radio waves. II PROPERTIES Electromagnetic waves need no material medium for their transmission. Thus, light and radio waves can travel through interplanetary and interstellar space from the Sun and stars to the Earth. Regardless of their frequency and wavelength, electromagnetic waves travel at the same speed in a vacuum. The value of the metre has been defined so that the speed of light is exactly 299,792.458 km (approximately 186,282 mi) per second in a vacuum. All the components of the electromagnetic spectrum also show the typical properties of wave motion, including diffraction and interference. The wavelengths range from billionths of a centimetre to many kilometres. The wavelength and frequency of electromagnetic waves are important in determining their heating
Determination of the acceleration due to gravity (g)
Determination of the acceleration due to gravity (g) By-nanding Li Introduction Gravity is the force at which the earth attracts objects towards it; also know as the weight of objects. When objects fall towards the earth, their acceleration increases because of the gravity. This acceleration due to gravity is dependent on the object's mass. A free falling object, if gravity s the only force acting on an object, then we can know the object will accelerate at a rate of 9.81ms-2 down toward the centre of the earth, this is known as acceleration due to gravity and is given the symbol 'g'. We can find the force causing this acceleration using: F = ma And weight for the object: G = mg Where the 'm' is the mass of object and 'g' is the acceleration due to gravity. However, acceleration due to gravity is not the same through out the universe. The moon has a smaller acceleration due to gravity than the earth. If we were to drop a stone on the moon, it would fall more slowly. This does not mean the mass of the stone is changed from the earth to the moon, this means the moon has less attraction to the stone and the acceleration due to gravity on the moon is about on-sixth of that on the earth: g moon = 1.6 ms-2 In this investigation, I am going to determine the acceleration due to gravity on the earth by using an electronic timer and varying its height of dropping.
Investigation to determine the viscosity of glycerol.
2007 IMPACT OF TEMPERATURE ON VISCOSITY "Viscosity is the virtue by which a fluid offers resistance to the motion of a solid through it." This document reports on an experiment that examined the relationship between temperature and viscosity. The terminal velocity and up-thrust experienced by a sphere of fixed weight and radius was calculated by dropping it into a measuring cylinder filled with glycerol heated to different temperatures. Using Stokes Law viscosity corresponding to each temperature level was worked out. This generated a range of data points with viscosity corresponding to each temperature level. These data points were statistically analysed. The results corresponded to those indicated by theory i.e. temperature and viscosity are inversely related; as temperature increased viscosity decreased. This report is in five sections. The first details the plan and the science on which the experiment is based. The second describes implementation while the third analyses the results. The fourth section evaluates the both the experiment and its results. The fifth concludes. Plan .1 The Question Is viscosity affected by temperature? When temperature increases does viscosity decrease or increase and if it does are the changes systematic or random? These are the questions I investigate in this experiment. .2 Key Concepts Archimedes' principle "A body immersed in a
Rules, Regulations and Scoring Systems of boxing.
Unit 11: Practical Sport Rules, Regulations and Scoring Systems Lee Potter Craig Atherton SPORT: MUAY THAI BOXING The Ring Size A four sided square. A national contest 6.10 metres x 2. An International contest 7.30 metres x 2. Floor and Corners The minimum floor height should be 4 feet and a maximum of 5 feet. Corner posts should have a diameter between 10 to 12.70 centimetres with a height of 58 inches from the ring floor. Ropes Each rope will be covered by a soft or cushioned material and has to join by two strong cords of 3-4 cms diameter and at an equal distance from each other. Ring Accessories Two towels, water or sprays, tables and chairs for officials, alarm bell, two stop clocks and score sheets. There are several more but these are the basic accessories needed. Boxing gloves requirements Mini Flyweight - Junior Flyweight 6 ounces (132 grams) Featherweight - Welterweight 8 ounces (227 grams) Junior Middleweight and upwards 10 ounces (254 grams) Heavyweight + Super heavyweight 12 ounces (264 grams) Wai Kru Prior to the start of every round the athletes must perform the wai kru accompanied by the Thai traditional music. Rounds A Muay Thai contest will consist of five rounds, three minutes each round with a two minute break between each round. Any stoppage during the contest for any reason will not