Ex. 5. Read the text. Match the nouns in bold with the correct definitions.
A battery pushes electrons round a circuit. The flow of electrons is called a current. Current is measured in amperes (A).
Potential difference (PD), or voltage, is measured in volts (V). the greater the PD across a battery, the more potential energy each electron is given. The greater the PD across a bulb or other component, the more energy each electron loses as it passes through.
To make current flow through a conductor, there must be a potential difference (voltage) across it. Copper connecting wire is a good conductor and a current passes through it easily. However, a similar piece of nichrome wire is not so good and less current flows for the same PD.
The nichrome wire has more resistance than the copper.
a. a unit for measuring the force of an electric current
b. the opposition of a piece of electrical equipment to the flow of direct current
c. the flow of electricity through a wire
d. the unit for measuring electric current
e. a substance that allows electricity to pass along it or through it
f. the complete path of wires and equipment along which an electric current flows
Ex.6. How do you say it?
= is, equals, comes to. ½ = 0.5 One half equals point five.
׃ divided by, over. 10: 5 = 2 Ten divided by five is two.
· times, multiplied by. 10 · 5 = 50 Ten times five equals fifty.
+ and, plus, add. 10 + 5 = 15 Ten and five comes to fifteen.
- minus, less, subtract. 10 – 5 = 5 Ten less five is five.
Do the calculations by yourself and read them out:
1. 1,520: 20 = 4. 562 – 234 =
2. 150 · 30 = 5. 1,845 : 15 =
3. 325 + 720 = 6. 83 · 50 =
Дата добавления: 2015-08-01; просмотров: 1679;