- Sticker info
Q. Most plug-in electrical devices in your home or school have a sticker on the bottom or back that describes some of their electrical characteristics. Find one near you and share it. What can you understand about the device from looking at this sticker?
The device in consideration is an HUAWEI travel charger. The charger indicates that it will require an electricity input of 100 – 240 volts. Its output is 5.0 V, and a current of 400mA. This means that if the input and output conditions are not met, the device may be destroyed or not work properly.
Q. As this is the last discussion posting, the topic covers the entire course. Choose a career that uses some of the physics that you have learned about in this course. In at least two paragraphs, describe the career, including how it uses physics, the required education, the approximate salary range, and whether you think it would be a good career to choose. You can pick one of the careers listed below or choose another one that interests you. Please cite any references you use.
An electrician is someone that works with electricity and electrical appliances. Electricians install and carry out maintenance work on electrical systems at home, business facilities and factories. They need to understand how basic electrical systems work. Some electricians begin by going to a technical school, and they then proceed to a four-year apprenticeship. In the U.S., apprenticeship requires at least 144 hours of technical training and 2,000 hours of remunerated on-the-job training (BLS).
In the U.S., the median pay for electricians in the year 2010 was USD 23.20 per hour. Their job outlook for the period 2010 to 2010 is 23%; faster than the average job outlook in the U.S. (BLS). In view of this, I think that being an electrician is a good career to choose. A career as an electrician is least affected by prevailing economic conditions; given that electricity is a vital utility.
- Electric Circuits
Q. The following website contains a bunch of analogies meant to help students visualize or understand different aspects of electric circuits. Pick one and post what you thought of it. Did it help your understanding? Do you think it is a useful tool?
- Furry Elephant: The uneven ground analogy
I think this analogy puts into perspective what happens when current flows in a given circuit. The bumps and obstacles in an uneven ground affect the movement, so do resistances in the way of current flow. I think this analogy is a useful tool.
Q. Many of the electrical devices we commonly use are powered by batteries. Find a battery-driven device and share its characteristics. How many batteries does it use and of what type and voltage? How much current can these batteries provide (you will have to research this). In your device can you tell if they are wired in parallel or in series? How much voltage do you think this device requires? How much current do you think it can draw?
The device into consideration is a torch; which uses dry cell batteries. The batteries in a torch are connected in series. The number of batteries in a torch depends on the size of the torch and the amount of light it is supposed to produce. A nominal dry-cell battery has 1.5 volts, implying that a torch with two dry-cell batteries will have 3 volts (1.5V * 2); when connected in series. Current (I) is calculated as the voltage (V) divided by the resistance (R) in a given circuit (I=V/R). Given that current is the same in a series connection, if one dry-cell battery produces 0.1A the current in the torch circuit will be 0.1A (Fitzpatrick).
Q. Write a paragraph discussing one of the aspects of MRI technology
Magnetic Resonance Imaging (MRI) is a technique of medical imaging used to analyze the anatomy and functioning of the body in both its healthy and unhealthy states. MRI uses scanners that have powerful magnetic fields as well as radio waves to come up with body images. This technique is widely used in medical practices for diagnosis, staging of the disease and follow-up. This technique does not expose the body to ionizing radiation (Hornak).
- Electrical Safety
Q. Choose one item related to electrical safety and provides a brief description of it, including why it is used and how it protects consumers or electrical workers. Be descriptive! Don't just say "plug covers keep babies from getting shocks" — discuss the voltages and currents involved and how the device's electrical properties prevent injury. You may choose one of the devices listed below or another device that interests you. Your answer should be about one paragraph long and must be in your own words. Please cite the references you use.
A fuse is a resister connected in a given circuit to protect an electrical appliance from damage. When a given appliance is connected to a power source, it is prone to risks of power surge. A fuse only allows power within a given voltage, and current range to pass through it. When this limit is exceeded, the fuse blows off. This breaks the circuit before the damage could be done on the given appliance.
- Right hand rule
Q. What do you think about the different variations on the right hand rule we have learned? Are you keeping them straight in your mind? How?
The variation of the right hand rule is interesting because it is thought provoking. One needs to make sure that no matter the orientation of the right hand, the thumb always points at the direction of the force, the middle finger at the direction of the velocity and the index finger at the direction of the magnetic field.
- Magnetic fields
Q. Choose and research one of the following topics related to magnetic fields. Summarized your findings in at least one paragraph your findings and thoughts in your own words. Please cite the references you use.
- How does Earth's magnetic field affect the Northern lights?
Northern lights occur when the earth’s magnetic field interacts with the flow of particles from the sun that are highly-charged (also called the solar wind). The interaction of the solar wind with the atmospheric molecules causes visible light as an energy emission. The earth’s magnetic field accelerates the flow of charged particles from the sun, at the upper atmosphere, to produce light (LOC).
- Electrical energy uses.
Q. Choose and research one of the following questions and write two paragraph summarizing your findings and thoughts in your own words. Please cite the references you use.
- The environmental impact of generating electricity with solar panels
Solar energy resource is a clean and sustainable energy production; free from hazardous emissions to the environment. Solar energy helps reduce the possible impacts of greenhouse gas emissions and pollution that could come from combustion of fossil fuels. Photovoltaic (PV) solar cells and concentrating solar thermal plants (CSP) are some of the technologies used in solar power production.
Some of the production negative impacts associated with the production of solar power include land use and loss of habitat, and the use of dangerous materials in the manufacture of solar power equipment. Solar production plants require large tracks of land to produce utility-scale power. This may interfere with the existing land uses. Clearing and grading of land may lead to soil compaction and enhanced runoff and erosion (Solar PEIS).
BLS. “How to become an electrician”. Bureau of Labor Statistics. Web. 17 Nov. 2013
Fitzpatrick, R.. N.p.. Web. 17 Nov 2013. <http://farside.ph.utexas.edu/teaching/302l/lectures/node57.html>.
Hornak, J.. N.p.. Web. 17 Nov 2013. <http://www.cis.rit.edu/htbooks/mri/inside.htm>.
LOC. “What are solar lights?” The Library of Congress. Web. 17 Nov. 2013
Solar PEIS. “Solar Energy Development Environmental Considerations”. Solar Energy Development Programmatic EIS, Information Center. Web. 17 Nov. 2013