Electricity project helps others amazing.pptx

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1. Electricity - CH 14 Aarush.D - Vihaan.C - Ujjval.A - Rishanth.M V

2. index Electrons 2. Early Investigations With Electricity 3. Simple Circuits 4 . Amperes 5 . Measuring Currents 6 . Lamps And Current Size 7 . Other Circuit Components V I

3. Answer - Firstly, we have the speed at which the electricity moves through the conductor. In this case, the answer is that electricity moves almost at the speed of light itself. To put it in numbers, it travels at 670,616,629 miles per hour. ‹#› Ever wondered how fast does electricity travel? V

4. Electrons 1 V

5. Introducing the Electron The idea of the atom was first raised by the Greek philosopher Democritus in around 400 BC . Since then, many discoveries have been made about atoms. Here is one which will help in our study of electricity. ‹#› ELECTRONS Diagram V

6. Electrons Introducing The Electron An atom has two parts. In the center of the atom is a part called the nucleus. Around the nucleus are particles that are much smaller than the nucleus-these are called electrons. ‹#› V

7. Electrons Electrons On The Move Scientists' first investigations were on electricity that, once generated, did not move. This electricity is called static electricity. ‹#› V

8. Electrons Conductors And Insulators It did not take scientists long before they discovered how to make electrons move through some materials, which they called electrical conductors, and until they identified materials that did not let electrons pass, which they called electrical insulators. The device that was invented to drive the electrons is called a cell, and when a group of cells is linked together, they form a battery. The moving electrons form a current of electricity. ‹#› Conductor V

9. Early Investigations With Electricity 2 V

10. Early investigations with electricity Luigi Galvani (1737-1798) believed that he had discovered 'animal electricity'. Galvani studied how human and animal bodies were constructed, but he also had a machine which generated static electricity in his laboratory. He discovered that when the machine was working, the muscles in dissected frogs' legs twitched. He also discovered that the muscles twitched when they touched two different metals, such as copper and iron. From his observations, he concluded that the muscles contained electricity. ‹#› V

11. Simple Circuits 3 U

12. Simple circuits Simple circuits are used in science to investigate the properties of electricity and the effects of bringing different electrical components together. The components in simple circuits are cells, wires, switches, lamps, buzzers and ammeters. The wires of the circuit are composed of atoms that are held tightly together, but around them are many electrons that are free to move. ‹#› U

13. Simple circuits The metal filament in the lamp and the metal parts of the switch also have free electrons. When the switch is closed, the wires on either side of the switch are linked by metal contacts and a path is made, along which the electrons can flow. you open the switch, the lamp goes out. The path is broken and the electrons cannot flow. The energy to move the electrons comes from the cell. The chemical reactions that take place in the cell make the electrons leave the cell at the negative terminal when the circuit is completed. They push their way into the wire and move the other electrons along, creating a flow or current of electricity. At the positive terminal, electrons are drawn back inside the cell. The wire in the lamp filament is more resistant to the flow of electrons than the other wires in the circuit. This means that it acts to stop the electrons moving freely. ‹#› U

14. Simple circuits The energy to move the electrons comes from the cell. The chemical reactions that take place in the cell make the electrons leave the cell at the negative terminal when the circuit is completed. They push their way into the wire and move the other electrons along, creating a flow or current of electricity. At the positive terminal, electrons are drawn back inside the cell. The wire in the lamp filament is more resistant to the flow of electrons than the other wires in the circuit. This means that it acts to stop the electrons moving freely. ‹#› U

15. Amperes 4 V

16. Amperes The rate at which electrons flow through a wire is measured in units called amperes. This word is usually shortened to amps and the symbol for it is A. One amp is equal to the flow of 6 million, million, million electrons passing any given point in the wire in a second! ‹#› V

17. Measuring Currents 5 V

18. Measuring Currents The current flow in a circuit is measured using an instrument called an ammeter. This is a device that has a coil of wire set between the north and south poles of a magnet. The coil has a pointer attached to it and it turns when a current passes through it. The amount by which the coil turns depends on the size of the current and is shown by the movement of the pointer across the scale. ‹#› V

19. Measuring Currents When an ammeter is used, it is connected into a circuit with its positive (red) terminal connected to a wire that leads towards the positive terminal of the cell, battery or power pack. It is always connected in series with the component through which the current flow is to be measured. Ammeters usually have a very low resistance so that the current passes through them without affecting the rest of the circuit. ‹#› Ammeter D- DEVSOTH

20. Lamps and Current Size 6 D-DEVSOTH

21. Lamps and Current Size ‹#› The wires connecting the components in a circuit have a low resistance. while the wires in the filaments of lamps have a high resistance. When lamps are connected in series, their resistances combine - they add up. They therefore offer a greater resistance to the current than each lamp would separately The size of the current flowing through a circuit can be estimated by looking at the brightness of the lamps in the circuit. A lamp shines with normal brightness when it is connected to one cell as shown in Figure 14.12a. The lamp shines more brightly than normal when it is in a circuit with two cells. D-DEVSOTH

22. Other Circuit Components 6 R

23. Other Circuit Components There are many components that can be added to circuits. If you made the lemon battery, you used one to test it - the LED or light- emitting diode. It performs the same task as a lamp and is found in many complicated electrical circuits, LEDs are also used in electrical devices where it is the lamp that shows that the device, such as a TV or a kettle, is switched on. A buzzer is an electrical device in which one part vibrates strongly when an electric current passes through it. The vibrations produce the sound. ‹#› Circuit Board R

24. ‹#› a U , V,D,R

25. ‹#› Oh, you thought we were done? We aren’t. Our friends Aarush and Rishanth have a surprise for you!

26. Question and Answers By Aarush Devsoth, Vihaan Chivukula, Ujjval Adiraju and Rishanth Moole

27. Topics Electrons Conductors and Insulators Simple Circuits Circuit Diagrams Amperes Measuring Current Lamps and Current Size

28. Electrons

29. Q.1 Who raised the idea of an atom?

30. Answer - A Greek Philosopher Democritus

31. Q.2 How many parts does an Atom have?

32. Answer - An Atom has 2 parts.

33. Q.3 What are the parts of an Atom?

34. Answer - Nucleus and Electrons.

35. Conductors and Insulators

36. Q.1 What are electrical conductors?

37. Answer - Materials which allow electrons to move through.

38. Q.2 What are Electrical Insulators?

39. Answer - Materials which do not let electrons pass through.

40. Q.3 What is a cell?

41. Answer - A device used to drive the electrons.

42. Q.4 What is a current of electricity?

43. Answer - Moving Electrons

44. Simple Circuits

45. Q.1 What are the components of Simple Circuit?

46. Answer - Wires, Switches, Lamps, Buzzers and ammeters

47. Circuit Diagrams

48. Q.1 How many symbols are there for a simple circuit?

49. Answer - There are 5 symbols

50. Q.2 What is this?

51. Answer - Cell

52. Q.3 What is this?

53. Answer - Connecting Wire

54. Q.4 What is this?

55. Answer - Lamp

56. Q.5 What is this?

57. Answer - Alternative Lamp Symbol

58. Q.6 What is this?

59. Answer - Switch

60. Amperes

61. Q.1 What are Amperes?

62. Answer - The rate at which electrons flow through a wire is measured in units called Amperes.

63. Measuring Current

64. Q.1 What is an Ammeter?

65. Answer - The current flow in a circuit is measured using an instrument called Ammeter.

66. Q.2 Do Ammeters have low or high resistance and Why?

67. Answer - They have low resistance so that the current passes through them without affecting the circuit.

68. Lamps and Current Size

69. Q.1 Lamps have high or low resistance?

70. Answer - They have High resistance.

71. Q.2 Which lamp is glowing bright and why?

72. Answer - The second one because it has 2 cells and one lamp which makes the lamp to have more current in it.

73. Redemption Questions

74. Q.1 In which country is the pink lake?

75. Answer - Australia

76. Q.2 Fastest Car on Earth

77. Answer - Bugatti Supersport 300+

78. Q.3 First Human on Earth

79. Answer - Homo Habilis

80. Q.4 What’s the Time now?

81. Answer - Open Ended Question

82. Q.5 Fastest Train in the World

83. Answer - Shanghai Maglev

84. Q.6 Oldest God on Earth

85. Answer - Yahweh

86. Textbook questions

87. Q1 - What other conclusion could Galvani have drawn about his work on metal and frogs’ legs? Ans: He could have said that frogs’ legs contain static electricity , instead of describing them as a conductor .

88. Q2- What did Volta take from Galvani’s experiment to make his first device? Which material that Galvani used did Volta change in the first device? Ans: He tested them with metals, just like Galvani did. But he had changed the material for testing from frogs’ legs to a salt solution.

89. Q3- What idea did Davy have after learning about the experiment of Nicholson and Carlisle? Ans: He thought that Nicolson’s and Carlisle’s discovery, of electricity splitting into a substance could be used.

90. Q4- How did the study of electricity help the study of chemistry ? Ans: Now, chemists knew that new substances that they found could help finding a new conductor of electricity.

91. Q5- Describe the path of an electron around the circuit in Figure 14.8 when the switch is pressed down? Ans: The electron is going through the switch’s metal panel to light up the bulb.

92. Q6- How does the wire in the filament behave differently to other wires in the circuit when the current flows? What property of the wire accounts for this difference? Ans: A) It slows down the electrons flowing and makes them rub and push against the material in the wire. Ans: B) The wire in the bulb is resistant to the flow of electrons than other wires in the circuit.

93. Q7-In Figure 14.10 the bases of the cells(on the right) are the negative terminals and the caps (on the left) are the positive terminals. How can you distinguish between the positive and negative terminals in a cell in circuit diagram in Figure 14.9?

94. Q8- To think about current and electron flow, try these simple calculations. How many electrons are flowing per second past a point In a circuit in which there is a current of: 0.5A 5A 30A ; Ans: A) 3 million Ans: B) 30 million Ans: C) 180 million

95. Q9-Towards which terminal of the power supply should the negative (black) terminal of an ammeter be connected? Ans: The negative terminal.

96. Q10-A wire carrying a current of electricity can be described as being similar to a stream carrying a current of water. In what ways are the wire and the stream similar? Ans: They both flow something. (Stream flows water, wire flows electrons) PS: Water is a great conductor of electricity, but makes the electrons flow in unnecessary ways.

97. Q11-Predict the brightness of the lamps in the circuits in Figure 14.13 compared with that of a single lamp in a circuit with one cell. Use one of the following descriptions in each case:very dim,dimmer,the same,brighter, very bright. (All the lamps are identical and all the cells have the same voltage.) Ans: The one with one cell would be the dimmest.

98. Q12-Compare the circuit in Figure 14.14 with the one in Figure 14.13b.Do you think the lamps will glow with the same brightness? Explain your answer? Ans: Yes, because both have 2 battery cells.

99. End of Chapter Questions

100. Where would you find an electron in an atom? Electrons are found outside the nucleus. Q1.

101. What materials let electrons flow through them? Metals like copper, iron, gold, aluminum, and silver allow electrons to flow through them. Q2.

102. What did Alessandro Volta replace muscles with in his experiment? Alessandro Volta replaced the muscles with a salt solution. He arranged a row of bowls of salt solution with copper strips and zinc dipping in each one. Q3.

103. How does this component show that electricity is flowing? The multimeter tests continuity by sending a little current through one probe, and checking whether the other probe receives it. If the probes are connected either by a continuous circuit, or by touching each other directly, the test current flows through. Q4 A

104. What component is used to test to see if a lemon battery produces a current of electricity in a circuit? A multimeter can be used. Q4 B

105. What is the circuit component which is used to start/stop electricity flow? The switch. Q5.

106. When you set up a circuit, why should everything be fastened? An electrical circuit must be a closed circuit in order for current to flow through it. If any of the components are not connected properly, it can result in an open circuit. Q6.

107. What is the short form and symbol of ampere? The short form of ampere is amp/s and the symbol is A. Q7.

108. How would you measure current flow in a simple circuit with an ammeter? The electric current in one part of a circuit is measured with an ammeter, which gives a reading in ampere. To take the measurement, a gap is made in the circuit and the ammeter is connected into that gap, so that the charged particles moving around the circuit must pass through the meter. Q8.

109. How is the symbol for a buzzer different from the lamp symbol used in the circuit diagrams? The buzzer symbol is a semi-circle shape while a lamp symbol is a circle with a cross inside it. Q9.

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