Electromagnetics 11-ES 207

1. Electromagnetics11-ES 207 L- T-P : 3-1-0 Credits: 4 Bhanu Prakash Assoc. Professor EEE Department

2. Session Learning Objectives: (points to be discussed) • Need of “Electromagnetics (course)” • Principle of generation • Classification • Sources of Electromagnetic waves • Advantages & Disadvantages • Applications Bhanu Prakash @ K L University

3. Need of “Electromagnetics” Study ? Electromagnetic fields (EMF) are all around us. We need them to see, to listen to radio and watch television, to communicate using mobile phones, and to run motors, fans, relays etc. we generate them every time we turn on a light switch or use an electric appliance. Bhanu Prakash @ K L University

4. Faraday's law of induction: (1830s) Explanation-1 Explanation-2 Bhanu Prakash @ K L University

5. How to produce/ generate/ induce Electric Field ? Bhanu Prakash @ K L University

6. Electric Fields: • Electric fields arise from voltage (Current Carrying conductor) • An electric field can be present even when a device is switched off. • Field strength decreases with distance from the source. • Most building materials shield electric fields to some extent. Bhanu Prakash @ K L University

7. How to produce/ generate/ induce Magnetic Field ? Bhanu Prakash @ K L University

8. Magnetic Fields: • Magnetic fields arise from current flows. • Magnetic fields exist as soon as a device is switched on and current flows. • Field strength decreases with distance from the sources. • Magnetic fields are not attenuated by most materials. Bhanu Prakash @ K L University

9. Which of the following is Electric field or Magnetic field or both? Fig.-2 Fig.-1 Fig.-3 Fig.-4 Bhanu Prakash @ K L University

10. Types of Electromagnetic Radiations • AM and FM radio waves (including TV signals) • Cell phone communication links • Microwaves • Infrared radiation • Light • X-rays • Gamma rays • What distinguishes these from one another? Bhanu Prakash @ K L University

11. i.e. Classification Bhanu Prakash @ K L University

12. Is there any insulation for Current? Is there any insulation for Field (Flux) ? Bhanu Prakash @ K L University

13. Which is most liking place in your Home? Kitchen room Bed room Hall Bathroom Bhanu Prakash @ K L University

14. Sources of Electromagnetic fields Bhanu Prakash @ K L University

15. Sources of Electromagnetic fields Contd…… • computers and related equipment • computer screens (especially the older types), • information networks • electrical appliances (including TV's) • electronic equipment • Cell phones • cell phone masts • radio and TV transmitters • microwave ovens • microwave transmitters or ovens, • house-wiring • high and low voltage power lines • cars, motor cycles, buses, trains, planes. • high voltage transformers, • transmission cables & Lines • pylons. Bhanu Prakash @ K L University

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17. What are the sources of EM waves in this Lecture hall? Bhanu Prakash @ K L University

18. Field distributions Electromagnetic fields inside a Motor Electromagnetic fields inside a desktop computer The H-field on the whole surface of an airplane Bhanu Prakash @ K L University

19. Disadvantages Bhanu Prakash @ K L University

20. Which is most liking place in your Home? Kitchen room Bed room Hall Bathroom Bhanu Prakash @ K L University

21. Electromagnetic field radiation (EMF) is emanating from virtually every single electrical appliance, computer, electric wire, and especially high voltage lines (overhead and buried), which are carrying current. EMF is specifically causing cancer in children and in older adults and may be triggering countless other immune deficiency and psychological diseases and disorders in anyone in close proximity. Many scientists warn people not to live within 200 yards (190m) of high voltage power lines. Of 35 international research studies on electric field radiation, 33 established a conclusive link between brain tumors, leukemia, and other forms of cancer. Bhanu Prakash @ K L University

22. The Bedroom Is Often the Most Dangerous Place In the Home Many researchers and scientists now feel that electromagnetic field radiation, both from within and without the bedroom, is the single biggest factor in poor sleep. And poor health. Look around your bedroom. Is there a clock radio on the nightstand near your pillow? A TV? A stereo? A cell phone below the pillow (bedmate)? A Laptop near to you/ your bed? Are there high voltage power lines with close to your residence? All or any of these electric sources can ruin your sleep and can substantially increase your risk of developing cancer and any number of diseases, both psychological and physical. Bhanu Prakash @ K L University

23. While you sleep, your body relaxes and is unconscious. In this state of vulnerability, research indicates you are 100-150 times more open to the damage of electromagnetic radiation that when you are awake. Children are often up to 1,000 times more sensitive to these fields when they are asleep. (TV screen in your bedroom will radiate energy all night...even after it has been unplugged. It can take hours or even days for the built-up voltage in the television to dissipate. ) • Do not leave any thing plugged in while you sleep, even if it is turned off. Outside high voltage power lines continually radiate EMF 24 hours a day. Bhanu Prakash @ K L University

24. Biological Effects of Electromagnetic Radiation • Protein Changes in Skin • Excited Brain Cells • DNA Damage • Brain Cell Damage  • Aggressive Growth in Leukemia Cells • Increased Blood Pressure Harmful Effects of ElectroMagnetic Radiation • Salivary Gland Cancer • Brain Tumour • Lymphatic Cancer and Bone Marrow Cancer • Miscarriage • Asthma Bhanu Prakash @ K L University

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26. Size of the Substations 11KV/132KV 132KV/33KV 132KV/11KV 33KV/11KV Bhanu Prakash @ K L University

27. Advantages Bhanu Prakash @ K L University

28. Easy to generate, use, and applicable in many implements. • Easy hand rules to understand flow direction, force, and polarity too. • Can be used in incredibly small to very large situation (i.e. pacemakers or trains) • Electromagnetic energy is clean. It is not polluting Bhanu Prakash @ K L University

29. Applications: • Motors and generators • Transformers • Relays • Electric bells • Loudspeakers • Magnetic recording and data storage equipment: tape recorders, VCRs, hard disks • Scientific instruments such as MRI machines and mass spectrometers • Particle accelerators • Magnetic locks • Magnetic separation of material • Industrial lifting magnets • Electromagnetic suspension used for MAGLEV trains Bhanu Prakash @ K L University

30. Applications: Contd…. • Radars • Cooking (with microwaves) • Medical Imaging (X rays) • “Night Vision” (infrared) • Astronomy (radio, wave, IR, visible, UV, gamma) • Satellite Communication • TV Communication • Wireless Communication • Mobile Communication • Microwave Communication • This theory is also used in analysis and designing of antenna, transmission lines and wave guides. All that we experience through our eyes is conveyed by electromagnetic radiation… Bhanu Prakash @ K L University

31. Applications: (Medical) Contd…. • Magnetic resonance imaging used in diagnostic. In this case is used a static magnetic field (a few Tesla) with a radio frequency signal superimposed • Hyperthermia uses electromagnetic fields for the treatment of cancer by means of tissue heating; • Electric stimulation: the stimulation of the hippocampus by means of electric field can be used in some brain therapy like Parkinson or neurological diseases. • Pulsed electromagnetic fields can affect the osteoblaste proliferation for bone reparation and favorite the wound healing. Bhanu Prakash @ K L University

32. Points discussed : (Summary) Bhanu Prakash @ K L University

33. Doubts/Questions? Doubt is worst Enemy! If you still have enemies Send them to bhanu184@kluniversity.in Bhanu Prakash @ K L University