GED Practice

Get ready to learn!

It takes Maria 15 minutes to make a pair of earrings. She wants to make $30 per hour for her work. Which expression shows how much money she needs to make per pair of earrings?

A) 4(30/15)
B) 4/30
C) 15/30
D) 30/15
E) 30/4

You have a new home business selling widgets. You’ve invested $370 to start your business. Each widget costs you $3.50, and you can sell each widget for $8.95. Which equation will tell you how many widgets you need to sell to make your first $1,000 profit?

A) (8.95 – 3.50)x – 370 = 1000
B) 8.95x – 3.50x = 370
C) 1000(8.95x – 3.50x) = 370x
D) 8.95x – 3.50x = 1000
E) (8.95 – 3.50)x + 370 = 1000

Electricity happens because electrons move through substances. An electron is a stable subatomic particle in the lepton family having a rest mass of 9.1066 × 10-28 grams and a unit negative electric charge of approximately 1.602 × 10-19 coulombs.

Electronics is the study of the behavior of electricity in vacuum tubes and semiconductors. This study has made possible many of the inventions of the Twentieth Century - the radio, radar, cell phone, and computers.

Which of the following Twentieth Century communication inventions requires a knowledge of electronics?
(1) watch
(2) phonograph
(3) telephone
(4) telegraph
(5) None of the above

Many encyclopedias, dictionaries, and textbooks contain very clear statements about the nature of Electricity. They say electricity is a type of energy and electric current is a flow of energy.

The above statements are wrong. Yes, electrical energy does exist. However, this energy cannot be called “Electricity,” since Coulombs of electricity are very different from Joules of electromagnetic energy. They’re two different things, so the energy and the charge cannot both be the electricity. It’s not too difficult to demonstrate the mistake.

In a lightbulb, charges of electricity flow through the filament and back out again. None are lost. This electricity enters the light bulb through one wire, and the same amount of electricity leaves through the other wire. Yet the energy doesn’t act like this at all. The light bulb uses up the electric energy: the electrical energy flows into the bulb along both wires and is transformed into heat and light. The electrical energy does not come back out through the second wire and return to the battery.

How can dictionaries, encyclopedias, and textbooks make such a gigantic error about electricity?

ANSWERS
1. If an error becomes extremely widespread, and hundreds of thousands of people begin making the same mistake, then the error will become invisible.