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Magnetism
Magnetism is a class of physical phenomena that are mediated by magnetic fields. Electric currents and the magnetic moments of elementary particles give rise to a magnetic field, which acts on other currents and magnetic moments. Magnetism is used in components such as generators, speakers, etc. For more information, please refer to the document attached.
Ananya Dixit
Friction- A necessary evil
Notes - Quick Definitons Friction Whenever there is a relative motion between two bodies in contact. An opposing force comes into act called as force of friction. Friction arises only when there is a relative motion between two bodies in contact. It is always opposite to the direction of motion. Cause of Friction The cause of friction are:- I)The microscope irregularities between two surfaces in contact. II)The intermolecular force of attraction. The magnitude of force of friction depends on :- A)The nature of two surfaces in contact. B)Actual area in contact between them. C)The normal reaction force between the two surfaces. Types of Friction Friction is of following three types :- Sliding Friction Rolling Friction Fluid Friction Sliding Friction The force of friction which comes into act when one body slides over the other is called as sliding friction. Sliding friction is weaker than static friction. That’s why it’s easier to slide a piece of furniture over the floor after you start it moving than it is to get it moving in the first place. Sliding friction can be useful. For example, you use sliding friction when you write with a pencil. The pencil “lead” slides easily over the paper, but there’s just enough friction between the pencil and paper to leave a mark. Sliding friction is also of following types. :- A)Static B)Limiting C)Dynamic A)Static Friction It is the force of friction which comes into act when one body tends to slide over the other but actually there is no motion. B)Limiting Friction It is the maximum value of force of friction so long as there is no actual motion between two bodies in contact, i.e. maximum value of static friction. C)Dynamic or Kinetic Friction It is the force of friction which comes into act when one body actually moves over the other. It is independant of the velocity of the body. Rolling Friction The force of friction which comes into act between two bodies when one body rolls over the other is called as rolling friction. Force of rolling friction is less than that of sliding friction as the actual area in contact is less in that of rolling friction. Rolling friction is much weaker than sliding friction or static friction. This explains why most forms of ground transportation use wheels, including bicycles, cars, 4-wheelers, roller skates, scooters, and skateboards. Ball bearings are another use of rolling friction. Fluid Friction The force of friction which comes into act when one body moves in a fluid is called as fluid friction. A fluid is a substance that can flow and take the shape of its container. Fluids include liquids and gases. If you’ve ever tried to push your open hand through the water in a tub or pool, then you’ve experienced fluid friction. Angle of Repose Angle of repose is the angle made by the inclined plane with the horizontal such that the body placed over it begins to slide. Angle of friction Angle of friction is the angle made by the resultant of normal reaction force and force of friction with the normal reaction force To see the formulas of the above definitions, refer to the pdf given
Indian Cuisine- A vast repository
It is document highlighting different cuisines of India and a understanding about the Indian spices used in the cookery. When food plays a vital part in our day to day life, it is all the more necessary to know what goes in making of our food, who handles the matters related to the food in India, etc. And now when food has become involved in the scientific research, it is essential to have a knowledge on it for further use. Overall, this document is a whole repository on food starting from origin of cuisine to the adulteration of food. Hope that this pdf will assist you in gathering information about one of the most liked thing, Food :-)
Atomic Absorption Spectrometry- A useful tool in scientific research
Every year, we are listening to the news of ever increasing pollution levels. It creates havoc in different ways, somewhere it is form of smog(Delhi) while in other places it is in form of soil erosion, loud noise, etc. We also get continuous reports of how Pollution Control Department is trying to curb these pollution levels by imposing fines on industries, coming up with new bills to be passed in legislation, etc. On a scientific level,there, lies a method to treat the issues of contamination. This is Atomic Absorption Spectrometry which is quite a important method nowadays as researchers use it to detect heavy metals in water, soil and air. AAS Method is basically a technique used for the determination of single elements in the chemical compounds using the absorption of optical radiation(light) by free atoms in the gaseous state. The principle of the technique involves using atomic absorption spectrum of a sample in order to assess the concentration of specific analyte in it. And moreover, to establish the relation between measured absorbance value and the analyte concentration, it relies on Beer Lambert’s Law. AAS detects elements from samples through application of characteristic wavelengths of electromagnetic radiation from a light source. So, basically what happens in this technique? First of all, a sample to be analyzed is taken and converted to liquid (most commonly used) or gaseous form. The solution is drawn in through a small tube present in the front of the device and taken to nebulizer where the solution is broken up into a fine mist(similar to an aerosol spray). The fine mist is carried to the atomizer, such as flame, by a carrier gas. When the sample reaches the flame, the intense heat evaporates the sample and leaves a fine dry residue which are the atoms in the ground state. These ground state atoms are excited with the electromagnetic radiation of specific wavelength. Once excited, they absorb the radiation given to them. The amount of absorbance value is measured and it indicates the absorbance for a particular element. The electromagnetic radiation comes from a hollow cathode lamp which has argon or neon gas inside. And the flame is typically Acetylene gas or Nitrous oxide gas. Atomization using flame are also called as FAAS (Flame Atomic Absorption Spectrometry) The AAS method is extremely used in detection of heavy metals, for analyzing soil and plants for mineral necessary for growth. It is also applied , in forensic for substance identification, in food industry, for quality assurance and testing for contamination, in pharmaceutical, for detecting impurities in drugs. So, this method is quite useful and will be in the near future. When our environment has become hazardous, methods like AAS become important all the more. It is also necessary to come up with new scientific methods to combat the harm on our nature.
Writing Tips:- 5 Tips for Writing an Effective Essay
Writing an essay is dreadful, especially when one needs to write it for college admissions,scholarships or for projects. All sorts of questions run in mind. "How should I write? How should I start? What is the basic format?” So, here we are giving you 5 ready- to-start advice for writing a constructive essay. Following this tips will give you a smooth start to your composition and pave your way for a successful draft. The five mantras to a effectual essay are :- 1. Think deeply about the topic given When one chooses the topic, one should do a deep analysis on it before starting on it. How to approach the subject and start on it. Finally, evaluate your options. The goal of your essay should be clear. If your goal is to educate, choose a subject that you have already studied. If your goal is to persuade, choose a subject that you are passionate about. Whatever the mission of the essay, make sure that you are interested in your topic. 2. Prepare an outline of your ideas In order to write a successful essay, organize your thoughts. Prepare points of your ideas starting from introduction, body to conclusion. By taking what’s already in your head and putting it to paper, you are able to see connections and links between ideas more clearly. This structure serves as a foundation for your paper. Use either an outline or a diagram to jot down your ideas and organize them. 3. Start drafting according to the format Start writing according to format of the essay. Firstly, start with the introduction.The introduction should attract the reader’s attention and show the focus of your essay. Begin with an attention grabber. You can use shocking information, dialogue, a story, a quote, or a simple summary of your topic. Then comes the body of the essay. The body of your essay argues, explains or describes your topic. Each main idea that you write in your diagram or outline will become a separate section within the body of your essay. Then, finally, comes the conclusion. The conclusion of the essay is like the summary of whatever you wrote in your essay.Your conclusion should consist of three to five strong sentences. Simply review your main points. 4. Avoid cliched lines Most often people use the cliched lines in their essays. Like in the essays wrote for admissions, students often use the lines “I am passionate about….From childhood it has been my dream…” Although not all lines are cliched, but these lines have often been heard by admission officers. So, its better to use your own inner thoughts and express it in your unique lines. After all, every human is unique and has the capability to write unique lines, too!! ;-) 5. Add finishing touches Finally, check your essay for any grammatical errors .Check the order of your paragraphs. Your strongest points should be the first and last paragraphs within the body, with the others falling in the middle. Also, make sure that your paragraph order makes sense. If your essay is describing a process, such as how to make a great chocolate cake, make sure that your paragraphs fall in the correct order. Do proper attention to the format of the essay. For different essays, one needs to follow different formats. Lastly, regardless of technical details, write the essay with full passion (this is cliched :-) ). Your inner thoughts should be conveyed with the public. Hope you write good essays. Happy Essay writing!!