Applications of electromagnetic waves
- 2. Microwave Oven A microwave oven is an electric oven that heats and cooks food by exposing it to electromagnetic radiation in the microwave frequency range. This induces molecules in the food to rotate and produce thermal energy in a process known as dielectric heating.
- 3. Principle of Microwave Oven A microwave oven heats food by passing microwave radiation through it. Microwaves are a form of nonionizing electromagnetic radiation with a frequency in the so- called microwave range(300 MHz to 300 GHz). Water, fat, and other substances in the food absorb energy from the microwaves in a process called dielectric heating. Many molecules (such as those of water) are electric dipoles, meaning that they have a partial positive charge at one end and a partial negative charge at the other, and therefore rotate as they try to align themselves with the alternating electric field of the microwaves. Molecules rotations, vibrations and/or translation hit other molecules and put them into motion, thus dispersing energy.
- 5. Internal Structure of Oven
- 6. Working of Micro Oven https://youtu.be/kp33ZprO0Ck 1) Electrical energy in the form of low voltage alternating current & high voltage direct current is transformed & converted into direct current. 2) A magnetron uses current to produce micro wave with frequency 2.45 GHz with wavelength 12.24 cm. 3) A waveguide transfers power from the magnetron, where waves are formed, to the cooking chamber. 4) Stirrer which disperses microwaves inside the oven cavity. 5) The microwaves are reflected by metal walls are absorbed by food .
- 7. Effects On Food and Nutrients Does not reduce the nutritional value of foods any more than conventional cooking. In fact, foods cooked in a microwave oven may keep more of their vitamins and minerals, because microwave ovens can cook more quickly and without adding water. Glass, paper, ceramic, or plastic containers are used in microwave cooking because microwaves pass through these materials. Metal pans or aluminum foil should also not be used in a microwave oven, as the microwaves are reflected off these materials causing the food to cook unevenly and possibly damaging the oven. Materials Used for for Cooking
- 8. Solar Cell A solar cell, or photovoltaic cell, is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect.
- 9. Materials Used for Solar Cell 1) Silicon 2) Gallium Arsenide(GaAs) 3) Indium Arsenide(InAs) 4) Cadmium Arsenide(CdAs) Si GaAs CdAs
- 10. Most Common Material Used Material :- Silicon Abundant in nature Band Gap Efficiency Impact on environment Electrical Properties Silicon oxide forms 1/3 of earth crust 1.12eV 22% Non poisonous Withstand upto 125 o C
- 12. Construction of Solar Cell Glass
- 13. I- V Characteristics of Solar Cell Ideal Characteristics
- 14. Ohm’s Law:- V= IR R= 0 Ω I = Imax R= Rmax V = Vmax
- 15. Short Circuit Current (Isc)
- 17. P Power of Solar Cell
- 18. Fill Factor Efficiency η= 12 % to 14 %
- 19. Losses in Solar Cell
- 20. Types of solar cell
- 22. Uses of Solar Energy
- 23. X- Ray Radiography X-ray or radiography uses a very small dose of ionizing radiation to produce pictures of the body's internal structures.
- 24. During a radiographic procedure, an x-ray beam is passed through the body. A portion of the x-rays are absorbed or scattered by the internal structure and the remaining x-ray pattern is transmitted to a detector so that an image may be recorded for later evaluation. The recoding of the pattern may occur on film or through electronic means.
- 25. It is used to diagnose or treat patients by recording images of the internal structure of the body to assess the presence or absence of disease, foreign objects, and structural damage or anomaly. Dental examination Mammography Orthopedic evaluations To get idea about the structure of matter Bone fractures Uses Of X - Ray
- 26. Infections (such as pneumonia) Calcifications ( kidney stones or vascular calcifications) Some tumors Arthritis in joints Bone loss (such as osteoporosis) Dental issues Heart problems Blood vessel blockages Digestive problems