Electromagnetic field ppt

electromagnetic induction ppt free download and electromagnetic ppt presentation
Dr.DouglasPatton Profile Pic
Dr.DouglasPatton,United States,Teacher
Published Date:26-07-2017
Your Website URL(Optional)
Comment
Indraprastha Institute of ECE230 Information Technology Delhi Why Study Electromagnetics? This course is about electromagnetics (EM), the electrical foundation of Electrical and Computer Engineering, or, how electricity really works. Look into the black boxes. • Linear Circuit is a simple part of EM, so it was taught first. • However there are an increasing number of cases in ECE where circuit theory fails (e.g. faster computers, higher communications frequencies, power electronics, power system transients,), and therefore EM must supplement circuit theory. But, don’t worry… • Also EM is the basis for many devices (machinery, antennas, etc.), and one of the physical foundations of any active electronic device. Indraprastha Institute of ECE230 Information Technology Delhi Why Study Electromagnetics? Electrical Engineering is Applied Electromagnetics • As devices get smaller and smaller, and frequencies get higher and higher, circuit theory is less able to adequately describe the performance or to predict the operation of circuits. • At very high frequencies, transmission line and guided wave theory must be used in applications such as high speed electronics, micro/nano electronics, integrated circuits. • Other applications include: Fiber Optics, Microwave Communication Systems, Antennas and Wave Propagation, Optical Computing, Electromagnetic Interference, Electromagnetic Compatibility, Biology and Medicine/Biomedical Imaging. Indraprastha Institute of ECE230 Information Technology Delhi Why Study Electromagnetics? • As use of the electromagnetic frequency spectrum increases, the demand for engineers who have practical working knowledge in the area of electromagnetics continues to grow. • Electromagnetic engineers design: high frequency or optoelectronic circuits, antennas and waveguides; electrical circuits that function properly in the presence of external interference while not interfering with other equipment. • The electromagnetics technical specialty prepares future engineers for employment in industry in the areas of radar, antennas, fiber optics, high frequency circuits, electromagnetic compatibility and microwave communication. Electromagnetics is Everywhere Electromagnetics is fundamental to the advancement of electrical and computer technology Indraprastha Institute of ECE230 Information Technology Delhi Why Study Electromagnetics? Objective Introduce the basic principles of the electromagnetic phenomena in terms of a few relatively simple laws Outcome Students are well equipped : • to handle important practical problems in electrical & computer engineering • to gain physical intuition about nature around themselves Indraprastha Institute of ECE230 Information Technology Delhi What is Electromagnetics? • Electromagnetics is the study of Charges: (i) at rest (ii) in motion • The subject of electromagnetics may be divided into 3 branches: • Electrostatics: charges are at rest (no time-variation) • Magnetostatics: charges are in steady-motion (no time-variation) • Electrodynamics: charges are in time-varying motion (give rise to waves that propagate and carry energy and information) Steps in Studying Electromagnetics • Define basic quantities (e.g., E-field, H-field) • Define the rules of operation (mathematics) of these quantities (e.g., Vector Algebra, PDEs) • Postulate fundamental laws Indraprastha Institute of ECE230 Information Technology Delhi Why is Electromagnetics Difficult? Electric and Magnetic Field: • are 3-dimensional • are vectors • vary in space and as well as in time • are governed by PDEs (partial differential equations) Therefore → • Solution of electromagnetic problems requires a high level of abstract thinking • Students must develop a deep physical understanding Math is just a powerful tool Indraprastha Institute of ECE230 Information Technology Delhi Examples of Electromagnetic Applications Indraprastha Institute of ECE230 Information Technology Delhi Communication Technology Indraprastha Institute of ECE230 Information Technology Delhi Computer Technology Indraprastha Institute of ECE230 Information Technology Delhi Antenna Technology Indraprastha Institute of ECE230 Information Technology Delhi Military and Defense Applications Indraprastha Institute of ECE230 Information Technology Delhi EEG Biomedical Applications (Electroencephalography) measures the electrical Fat and activity produced by the Fibrograndular brain as recorded from Tissues electrodes placed on the scalp. Malignant Tumor ECG (Electrocardiogram) records the electrical activity of heart over time. Indraprastha Institute of ECE230 Information Technology Delhi Transportation • Levitated trains: Maglev prototype Indraprastha Institute of ECE230 Information Technology Delhi Localization and Sensing Indraprastha Institute of ECE230 Information Technology Delhi What are electromagnetic waves? magnetic field • Electromagnetic waves are transverse waves made up of electric and magnetic electric fields. field • All electromagnetic waves travel at the same speed. • In a vacuum (space), they travel at 300,000,000 m/s wave direction Indraprastha Institute of ECE230 Information Technology Delhi How do electromagnetic waves differ? • Different electromagnetic waves carry different amounts of energy. • For example, microwaves carry less energy than X-rays. • The amount of energy carried by an electromagnetic wave depends on the wavelength: • the shorter the wavelength, the higher its energy. • Wavelength and frequency are linked properties of a wave: the shorter the wavelength, the higher its frequency. • So, frequency also tells you about the energy of a wave: • the higher its frequency, the higher is energy. Do microwaves have a shorter wavelength than X-rays? Indraprastha Institute of ECE230 Information Technology Delhi What happens when waves hit a surface? • When electromagnetic waves hit a surface, they can be reflected, absorbed or transmitted. • How the waves behave, depends on their energy and the type of material. • For example, light waves are reflected by skin but X-rays pass straight through. • If electromagnetic waves are absorbed, some of their energy is absorbed by the material. This usually increases the temperature of the material. Indraprastha Institute of ECE230 Information Technology Delhi What is the electromagnetic spectrum? • The electromagnetic waves are grouped into types that have similar wavelengths and so have similar properties. radio visible gamma microwaves infrared X-rays ultraviolet waves light rays 100 m 10 cm 1 mm 0.01 mm 100 nm 1 nm 0.01 nm smaller wavelength → higher frequency → energy and hazard Electromagnetic waves form a continuous series in order of changing wavelength, frequency and energy. This series is called the electromagnetic spectrum. Indraprastha Institute of ECE230 Information Technology Delhi How do radio waves affect humans? • Radio waves are the longest-wavelength electromagnetic waves and mostly pass through the body. • They are not strongly absorbed and are thought to have no effect on the health of living tissue. • Microwaves are radio waves with short wavelengths. They are very slightly absorbed by the body and can cause a minor heating effect. • However, the microwaves produced by mobile phones have not yet been proved to cause health problems. Indraprastha Institute of ECE230 Information Technology Delhi How do infrared waves affect humans? • Infrared waves are absorbed by skin to a limited depth. They transfer their energy to the skin tissue warming it up. • This heating effect is detected by temperature-sensitive nerve endings in the skin. Infrared waves from this grill heat the surface of the meat. If the meat absorbs too much energy, it will be burnt. If skin is exposed to too many high-energy infrared waves, it will be burnt.

Advise: Why You Wasting Money in Costly SEO Tools, Use World's Best Free SEO Tool Ubersuggest.