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Web LinksUNIT 4: ELECTRICITY AND ELECTRONICSClick on a section below for related Web activities: Chapter 7:Current Electricity 7.9 Electrical Power and Energy 7.10 Investigation: Troubleshooting Electric Faults
Chapter 8: Electronics 8.8 Analog and Digital Systems
Unit 4 Review
CHAPTER 7: CURRENT ELECTRICITY p. 318 4. Another means of transforming mechanical energy into electrical energy is piezoelectricity. In this method, a mechanical force applied to layers of crystals forces charges to opposite sides. Piezoelectric technology is used in crystal microphones, some radiation detectors, force plates for testing the techniques of athletes, force sensors, and some cigarette lighters. Research piezoelectricity, and briefly describe one application.
Piezoelectricity: Applications This site describes the physics behind piezoelectricity, piezoelectronics, and lists the applications of piezoelectric materials. This site describes the history of piezoelectricity, applications with natural crystals, applications with piezoelectric crystals, and current technological advancements.
This site describes piezoelectricity, piezoelectric constants, soft versus hard ceramics, behaviour of a piezoelectric element, and applications of the piezo theory.
p. 320 AC Frequencies AC generators in North America force the electric charges to reverse direction at a frequency of 60 Hz. Some European countries use a frequency of 50 Hz. In the early days of electricity in North America, AC was produced at 25 Hz. When the system switched to 60 Hz, all devices with electric motors had to be changed, at great cost and inconvenience.
AC Generators: Design & Applications This page provides information about electricity, direct current (DC), alternating current (AC), frequency, and equations related to AC circuits, including the calculations of voltages, currents and power. This site explains the basics about AC generators, home standby systems, and features of AC generators.
p. 347 An interest in the heart can lead to different careers, for example, as a cardiovascular technician on a medical diagnostic team, or as a veterinary technician helping animals. Both paths lead to rewarding and highly trained professions. Mohawk College-Cardiovascular Technician This page lists general information about Mohawk College's Cardiovascular Technician program, the admission requirements and employment statistics, as well as information for employers and corporate sponsors. Career Matters-Medical Radiation Technologist This site outlines the job description, required education, specific duties, and possible career opportunities for cardiovascular technicians. It also provides a link that lists recommended high school courses students should take to prepare them for these careers. This page describes the veterinary technician program offered by Georgian College, admission requirements, program learning outcomes, and practical experience gained by graduates of the program.
Explore an Issue p. 349 Electrical Safety Standards (c) Look up CSA and UL on the Internet. What do these symbols stand for? Describe what else you discover about CSA or UL. This site describes CSA International, a leading provider of product testing and certification services. Learn about CSA in the United States, Canada, Europe, and Asia. This page describes CSA International, what it does, how its standards are developed, and how products and systems are tested before CSA certification.
Find out what UL stands for and how it ensures public safety and confidence. This page provides links to UL's Standards Technical Panels, and UL's Standard Department Web site.
p. 355 8. Search the Internet to find out more about appliances that display the Energy Star symbol. (a) State the standards that appliances in various categories must meet in order to display the Energy Star label. (b) Why do the requirements differ among categories? (c) Is a low standby power important in any of the categories? How do the Canadian requirements compare with the discussion of standby power in section 4.4, page 194? Explain your answer. This Energy Star home page provides comprehensive information about what the Energy Star symbol represents when found on appliances, lighting, cooling, heating, and in homes, and provides a link to the Energy Star identity guidelines. The International Energy Star Symbol Find out what the International Energy Star symbol means and why Natural Resources Canada's Office of Energy Efficiency promotes this designation across Canada.
Section Questions p. 357 9. Electric power distribution companies pay the market rate for electrical energy and, if possible, pass the charges on to the customers. (a) What conditions tend to make the rate rise dramatically? (b) In parts of England, the cost of electrical energy used during the day is nearly three times that for nighttime use. Owners of electric water heaters often choose to heat their water overnight because the process requires a large amount of electrical energy. How could this principle be applied in your area to reduce electrical energy use during peak demand periods? (c) Research a new technology called "remote interval metering," featured in some suburbs. This system keeps track of the electrical energy used in residential areas during different parts of the day. Do you recommend that this technology be available to all consumers? Explain why or why not. This site provides rates on residential electric, general lighting, and general power services for the State of Missouri. California OKs Temporary Gas, Electric Rate Hike This article describes the increase in the cost of electricity and natural gas for Californians and reasons for the price hike. It also provides links to related stories and sites. This site provides information on rates and repayment in the sale of electric power, the energy planning and management program, and legislation and regulations in marketing electricity. This Federal Energy Regulatory Commission site describes electric power regulations as outlined by the Federal Power Act, the Public Utility Regulatory Policies Act, and the Energy Policy Act. This article describes the remote meter reading system used in Australia.
p. 359 Electricians-both commercial and residential-can earn good hourly rates. Not only do electricians test and troubleshoot electrical systems, but they also maintain, design, and replace them. Some examples of where electricians are needed are for renovations, in construction, and working with heat, lighting, and alarm systems. Ontario Youth Apprenticeship Program This page describes the Ontario Youth Apprenticeship Program, and provides links to different opportunities available to students, including electricians. This site outlines the job description, required education, specific duties, and possible career opportunities for electricians. It also provides a link that lists recommended high school courses students should take to prepare them for these careers. Career Matters- Power Systems Electricians This site outlines the job description, required education, specific duties, and possible career opportunities for power system electricians. It also provides a link that lists recommended high school courses students should take to prepare them for these careers. Career Matters-Industrial Electricians This site outlines the job description, required education, specific duties, and possible career opportunities for industrial electricians. It also provides a link that lists recommended high school courses students should take to prepare them for these careers.
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23. Most Canadian homes use hot-water tanks that hold between 150 L and 270 L of water. The water, which is heated by electric current or natural gas, is kept heated, ready for use. An alternative method of heating water, commonly used in Europe, heats the water only as it is being used. This "tankless heating" uses natural gas. (a) Which of the two technologies operates in standby mode? (b) Which energy source, electric current or natural gas, is more efficient at heating water quickly? How can you tell? (c) Describe the main advantages and disadvantages of using tankless water heating technology. (Research will help.) This site provides information about Seisco's tankless water heaters, and their advantages and applications for residential and commercial uses. Efficient Water Heating Systems and Water Heaters This page describes Electro Silica's water and heating systems, and provides links to information on water heating systems, and purification systems. This site provides information on the different types of water heaters, including electric, solar, thermosiphon, tankless, and demand water heaters. Compare and contrast the characteristics of each. This site provides information about water heaters, compares fuel costs, and lists advantages and disadvantages of tankless water heaters.
CHAPTER 8: ELECTRONICSp. 369 Superconductors A superconductor is a material with no resistance to an electric current. Certain metals, alloys, and ceramics become superconductors at temperatures near -273 o C. Some compounds can become superconductors at higher temperatures. Once an electric current is started in a superconductor loop, it can continue for years. In the future, superconductors will likely be used in many applications, for example, making super-fast computer chips. This site provides introductory information about superconductors, their history, applications, and atypical superconductors of the future.
Superconductivity for Electric Systems This Oak Ridge National Laboratory (ORNL) site describes ORNL's high temperature superconductivity research and development, publications, reports, roadmaps, and future applications.
p. 369 Selenium Selenium is an inorganic trace element found in the human body. It is an antioxidant mineral that may help reduce the risk of cancer. However, those who take food supplements containing selenium must not exceed the recommended quantity. Too much selenium can cause hair and fingernail loss! This National Institutes of Health sites lists facts about dietary selenium, what it is, recommended dietary allowance for adults, current issues and controversies about the supplement, and risks associated with too much selenium. This Idaho Department of Health and Welfare fact sheet describes the health effects of selenium, its association with cancer, and the US government's recommendations to protect human health.
p. 376 Testing Conductivity Using an LED (b) Your circuit could have been constructed with an incandescent light bulb instead of an LED. On the Internet, research the benefits of using an LED instead of conventional incandescent bulbs in electronic equipment. Summarize your findings in a table
LEDs: A Preparation for a Brighter Tomorrow This site describes what LEDs are, how they produce light, advantages of LEDs as a light source, and applications and commercial uses of LEDs.
Utilizing Light Emitting Diodes In Today's Energy Conscious World This article describes how LED lamps are superior to incandescent lighting, as well as LED technology and its benefits.
Practice Questions
p. 377 6. (a) Describe the energy transformations that occur in the collection and use of hydrogen in a fuel cell that requires a rectifier circuit. Write the corresponding energy-transformation equation. (a) Follow the links from the Nelson Web site to Stuart Energy's Web site. Draw and label a flow diagram of the Stuart Energy fuel cell that requires a rectifier circuit. (b) What type of fuel cell does not require a rectifier circuit? Stuart Energy: The Power of Hydrogen This page describes Stuart Energy's power products and energy stations, transportation products, and industrial products.
p. 384 Viewing Vacuum Tubes To investigate how the technologies related to TV, radio, and other devices have changed, you can visit Web sites that show many types of vacuum tubes.
This article describes the basics of the vacuum tube, its internal structure, and its past and current uses. This site outlines the history of vacuum tubes and the scientists involved in its development. It also describes the tube and how it works.
This site describes the prevalence of vacuum tubes in early electronic devices. It also provides links to related articles. This page provides a brief description of the history of vacuum tubes and the scientists in the forefront of this innovation.
p. 388 Stray Capacitance A capacitor exists wherever two conductors are separated by an insulator. For example, when an insulated wire conductor is near the metal chassis of a power supply, together they form a capacitor. This type of capacitance is called stray capacitance or distributed capacitance . It exists in all electronic circuits and affects their operation. Focus on Technology: Stray Capacitance This article briefly describes stray capacitance and the physics behind it. Ask the Applications Engineer-Capacitance and Capacitors This page describes what stray capacitance is, how it works, and how it can be eliminated.
Try This Activity p. 389 Properties and Uses of Capacitors Research capacitors on the Internet, and set up a table to summarize the main properties and uses of several of the capacitors you find. Include a sketch of the shape of each capacitor. Ask the Applications Engineer-Capacitance and Capacitors This page answers some important questions about capacitors, the different types, and their effects. Also provided is a capacitor comparison chart with the advantages and disadvantages of each type of capacitor.
This page describes the function of capacitors, and lists and explains the most commonly used caps, including electrolytic, tantalum, polyester film, polystyrene, super capacitors, and more.
p. 393 Many Ontario community colleges offer Electronics Engineering Technology programs. With this diploma, you can choose from many exciting and interesting careers, for example, designing sound equipment or creating the designs on computer. Humber College of Technology and Advanced Learning This Humber College site allows you to search for specific programs, such as electronics engineering technology diploma and certificate programs; and lists admission and registration requirements. Seneca College of Applied Arts and Technology This Seneca College site provides information for students, businesses, and the community; as well as information about Seneca programs (i.e., the electronics engineering technology communications program), and career searches. This home page provides information about Mohawk College's full-time and part-time programs and courses, student services, application process, financial aid, and their graduate employment report. This page has information about an electronic engineering technology co-op program. Admission requirements, a virtual tour of their communications, micro-electric, and automatic control systems, and employment information is all available. Career Matters-Electronics Engineering Technologists and Technicians This site outlines the job description, required education, specific duties, and possible career opportunities for electronics engineering technologists and technicians. It also provides a link that lists recommended high school courses students should take to prepare them for these careers.
Did You Know?p. 396 Audio Frequency Range The healthy human ear is sensitive to sound frequencies from about 20 Hz to 20 kHz. Thus, the sampling rate of 44.1 kHz is high enough for sampling digital sounds heard by humans. The Physics Classroom: Sound Properties and Their Perception This site describes the properties of sound waves and the audible range of hearing for humans and other animals. This site explains what sampling rates are, the rates of various audio devices, and how the sampling rate affects the quality of the recording.
p. 399 Changing IC Technology While the invention of the transistor in 1948 revolutionized electronics, it cannot rival the impact of the integrated circuit, invented 10 years later. For the first time, all of the circuitry was packed into a single crystal. For example, a single microchip with a surface area of only 17 mm 2 , made in 1994, contained 9 million transistors. A similar number of the transistors developed in 1948 would cover an area larger than eight football fields.
This fact sheet describes the inventor of integrated circuits, how these circuits are made, and the impact they have made on the world.
This PBS site describes transistors, and the invention of the integrated circuit.
Career Connection p. 399 Computer systems support personnel are needed by many different types of companies, such as software developers, Internet service providers, and businesses. These experts provide help and advice to customers, troubleshoot, and analyze computer system problems and offer solutions. Career Matters-User Support Technicians This site outlines the job description, required education, specific duties, and possible career opportunities for user support technicians. It also provides a link that lists recommended high school courses students should take to prepare them for these careers. Humber College of Technology and Advanced Learning This Humber College site allows you to search for specific programs, such as computer software development diploma and certificate programs; and lists admission and registration requirements.
Did You Know? p. 401 Bits and Bytes A byte is a unit of digital data consisting of 8 bits. Storing one letter or one numeral in a computer requires about 1 byte of data. The capacities of files and drives of today's computers are measured in four multiples of bytes:
Notice that the prefixes kilo, mega, etc., do not refer to the same quantities as are used in SI. In the future, storage capabilities are expected to become even larger. Computers will have petabyte memories (PB, or 2 50 bytes), and maybe even exabyte memories (EB, or 2 60 bytes). Although this may sound impressive, it doesn't even approach the human brain's storage capacities. This page describes bits, bytes, how they work, and the binary system.
Data Structures and Number Systems This site describes bits, bytes, data structures, binary coded decimal, and status and Boolean variables. Did You Know? p. 401 Packets of Data When you send (or receive) information over the Internet, the data is first broken into small units called packets . These packets may travel different paths on their way through the telephone or cable communication network. When they arrive at their destination, often within seconds, the packets are put back together. This page explains what packets are and how they are used to transfer information through packet switched networks. This page explains how information flows over the internet in the form of packets, and the importance of the Transmission Control Protocol / Internet Protocol (TCP/IP).
Practice Questions p. 401 7. Electronic digital pens that allow the user to store many written pages in memory use microtechnology. Find out more about this application, and describe briefly what you discover.
This page describes the electronic pen, its advantages and disadvantages, and its uses in computers, cell phones, pagers, and web televisions. This article describes the electronic pen, how it was developed, and how it works. Did You Know?p. 402 Chip Payment Technology IC chips embedded in payment cards, such as credit and debit cards, protect against fraudulent use. Information on the chip is virtually impossible to copy, and purchases made at chip-enabled merchant terminals are very secure. This page describes what a smart card is, how it differs from magnetic stripe cards, and the three categories of smart cards in the market.
This page describes the semi-conductor technology that enabled the development of smart cards in areas such as banking and healthcare.
p. 407 23. A Canadian satellite called CubeSat is a cube only 10 cm on each side. Designers call this a picosatellite. Other small satellites are called nanosatellites or microsatellites, depending on their masses and dimensions. Research the CubeSat program on the Internet. (a) What mass ranges apply to the names pico-, nano-, and microsatellites? (b) Look at ICs on board this satellite; note especially RAM and storage capabilities. Describe briefly what you discover. This official site of the International CubeSat Project provides the most up-to-date information on the satellite program. New Technology Now Makes Launch of Space Satellites Affordable to the "Masses" This article describes the CubeSat satellite project, how these low-mass satellites were developed, and the advantages of using these as space satellites.
p. 417 37. "Smart textiles" are fabrics embedded with electronic components that accomplish a specific task. For example, a "smart blanket" has thin fibres that conduct current and generate thermal energy that can keep an ice fisher warm for hours. A "smart apron" uses integrated circuits and a built-in microphone to allow a person with a motor disability to operate kitchen appliances hands-free. (a) You have been asked to design a wearable, hooded electronic jacket. Describe the features you would like your jacket to have. Use your imagination! (think of sights and sounds, as well as the ability to monitor variables such as heart rate, location, and distance moved.) (b) Research smart textiles on the Internet. Briefly describe an interesting application you discover. Smart Textile develops textiles for industrial, technical, medical, or military purposes. Find out about the usability, wearability, and consequences of these intelligent clothing. Smart Textiles-Exploring the Potential for Smart Textiles Read about smart textiles and the advancements made by Soldier Warrior Systems Technologies, including electronic communication, and display devices embedded into soldier uniforms.
p. 418 41. Many people connect their personal computer system to an electrical outlet through a surge protector extension cord. (a) What is surge protection? (b) Why is it wise to have this type of protection for computers and other electronic devices? (c) Research surge protectors using a resource such as a reference book or the Internet. If necessary, change your answers in (a) and (b) above. (d) Based on your research, draw a diagram of a typical surge protector, and describe how the electrical and electronic components operate. This site explains how surge protectors work, the process of protection, surge sources, and how electronic systems are protected by these surge suppressors. Surge Protectors That Will Not Fail Find out how surge protectors are constructed, and how product standards are maintained.
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