Essential Questions 4.4

Anticipatory Set

Of all the engineering accomplishments over the past two hundred years, the one to have the greatest impact is the development of electrical systems. Factories had to be close to sources of water, not only for water power but heat engines at the time depended on steam to run. Electricity brought freedom to factories to go where they wished. It also brought freedom to people allowing them to work and play after the sun was gone, with safe light sources. It brought electric motors into our homes to make hard work easy, to chill, and cook food.



We take electricity for granted. The following is an excerpt from the book “Wonders of the Universe: A Record of Things Wonderful and Marvelous in Nature, Science and Art” Published by Cassell and Co. NY, © 1885, written just after Thomas Edison built the first generating station.



“When electricity is laid on to our houses and factories, like water and gas is now supplied to us-a state of things promised by sanguine electricians-we shall find many uses for it which neither water nor gas can afford, or can only give us at a prohibitory price. Electric illumination will naturally absorb first attention, but when we are supplied with the current for that, other applications will follow as a matter of course. Some clever people think that our cooking will be also done by electricity, in specially constructed furnaces. Such a thing may be possible, though hardly probable.”

Key Terms

Alternator
Analog
Current

Digital
Generator
Hysteresis

I/O
Interface
Load

Magnetism
Memory
Motor

Ohm's Law
Parallel
Power

Processor
Receiver
Rectification

Relay
Resistance
Semiconductor

Series
Solenoid
Strain

Stress
Switch
Synchronous

Transducer
Voltage
Watt's Law

Name


  1. How much electricity does your community use and what is the safest way for your community to generate electricity?


  1. What are the problems your community is having with its electrical supply and what do you think can be done about it?