CHAPTER - 12 ELECTRICITY HOTS Questions for Practice 1. Name a substance whose resistance almost remains unchanged by increase of temperature. 2. Name two special characteristics of heater coil. 3. A wire of resistance 4 ohms is bent to form a circle. What is the resistance between two diametrically opposite ends? 4. How does the resistance of a conductor change if its temperature is increased? 5. A current of 4A flows in a wire of resistance 60 ohms. Calculate electrical energy consumed in 2 minutes
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Phosphates are present in many natural waters‚ such as lakes and streams. Phosphates are essential to aquatic plant growth‚ but too much phosphate can lead to the growth of algae and results in an algae bloom. Too much algae can cause a decrease in the amount in dissolved oxygen in the water. Oxygen in water is affected in many different ways by phosphates Phosphorus is usually present in natural waters as phosphate(Mcwelsh and Raintree‚ 1998). Phosphates are present in fertilizers and laundry
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Density of Liquids II. Purpose/Background: The purpose if this lab was to determine the density of water and an unknown liquid. Density is defined as the mass of a substance divided by its volume. It is an intrinsive property of matter and is used to specifically characterize substances. III. Procedure: 1.We massed an empty 10mL graduated cylinder to the nearest .01g. 2.Then‚ we filled the graduated cylinder with 4.0-5.0 mL of distilled water‚ 3.massed it to the nearest 0.1 ml and 4. recorded
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In the summer of 1964‚ Lyndon B. Johnson signed the Civil Rights Act. This was a major turning point in the political parties‚ as it caused an undeniable shift as to which party held the majority of black voters. However‚ despite Lyndon B. Johnson being a democrat‚ he did not have the widespread support of his party. Out of the democratic representatives of the House and Senate‚ 64‚ and 69 percent of the representatives voted in favor of the act‚ respectively. On the Republican side‚ it was 80‚ and
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EXAMINATIONS FOR DEGREES AND DIPLOMAS October-November 2008 Mechanics of Solids First and only paper Time Allowed: THREE (3) hours Instructions: Answer all questions. -2- Question 1 Figure 1 Two circular A-36 steel1 rods are connected as shown in Figure 1. The rod CD has a diameter of 30mm. Both members are pin connected together at C (see figure detail). You are asked to determine: a b Identify what kind of structural member are AB and CD respectively. The maximum force
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Properties of Water Water is essential for life as we know it on earth. It is used by plants and animals for basic biological processes which would be impossible without the use of water. The origin of all life can be traced back to the water in the Earth’s precambrien seas. Water is also the universal solvent. It reacts with more elements and compounds than any other substance known to man. Water is a polar molecule made up of on atom of hydrogen and two atoms of oxygen. It is attracted
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Winkler method for dissolved oxygen determination Abstract In this study the group has determined the presence of oxygen in sample through a modified winkler method. The amount of oxygen is determined through a series of reaction. A body of water can sustain life if dissolved oxygen is sufficed. Depletions in dissolved oxygen can cause major shifts in the kinds of aquatic organisms found in water bodies. Introduction The amount of dissolved oxygen present in water or wastewater is essential
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Crystallization and Melting Points Organic Chemistry 221 9/19/2012 Intro/Purpose: The purpose of this lab was to use crystallization to separate a compound from a solvent and be able to choose the best solvent to do so. Then identify an unknown and verify purity using melting points. Solubility contributes to crystallization; because a solute has lower solubility at lower temperatures‚ which makes the solvent separate from the solution as a solid. This process is important to understand because
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flinnsci.com Liquid Chromatography AP Chemistry Laboratory # 18 Publication No. 10535A Catalog No. AP9093 Introduction In this experiment‚ liquid chromatography is used to separate the substances that are present in grape-flavored Kool-Aid®. First‚ the dyes responsible for the purple color‚ FD&C Blue #1 and Red #40 are separated. Then‚ in a second experiment‚ the other components of Kool-Aid®‚ the flavorings and citric acid‚ are separated as well. Concepts • Resolution • Liquid chromatography
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“When in Rome‚ do as the Romans do” is the famous axiom of St Ambrose‚ the very famous bishop of Milan in the 4th century. He advises that people should follow the traditional customs and decency of country where they choose to live. The knowledge about culture and customs of another country bring many benefits for immigrants. They can know the positive things they should do and the negative things they must avoid. This knowledge also makes them feel more freedom in a strange country. Nowadays‚ many
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