V. Translate the sentences. Mind one.
1. There are many insulating materials from which one may choose.
2. The new method is more efficient than the old one.
3. The element has a trouble. It operates badly. It should be substituted by a new one.
4. Some substances are efficient conductors, others, poor ones.
5. One uses special devices to measure current, voltage and resistance.
6. One knows that these installations do not operate on nuclear power.
7. One must choose only one of those variants.
VI. Fill in the gaps with: one, ones.
1. Some substances can attract metals. The _____we use to make magnets are iron, nickel and cobalt.
2. Which force is the ______ that holds the atmosphere in space?
3. Among scientists, physicists are the ______who are trying to unify all the forces.
4. ______ can reduce heat losses in a transmission line.
Speaking
VII. Discuss with your group-mates.
M. Lomonosov is a great Russian scientist.
Name all the discoveries in physics found by M. Lomonosov. You may use the following key words: zero, conservation, heat, light, electricity, motion, atmospheric electricity.
3 Fields and Forces
Reading
I. Read the following key words:
spinning, protons, electrons, nucleus, current, magnet, line up, behave, gravitation, the north, electromagnetism.
II. Guess if the following statements are true or false.
A needle is a magnet. ______________
“Like” magnetic poles attract. ______________
The centre of the Earth is a magnet. ______________
Electromagnetic force holds our body together. ______________
III. Read and translate the text.
1. We know that an atom is made from protons and neutrons in a nucleus, and electrons spinning around this nucleus. The protons have a positive electric charge and the electrons have a negative electric charge. The neutrons have no electric charge. As the electrons spin around the nucleus, they produce small currents. These currents create a magnetic field around the electrons and the atom. This magnetic field makes the atom behave like a small magnet.
2
.
Magnets can be natural or artificial.
The Earth, for example,
contains magnetic substances
in its nucleus. These substances, which are also
in our body, make our planet
a big natural magnet. That’s
why when you hang a bar
magnet from a thread in a horizontal
position, its north pole
points to the geographic north pole of the Earth. A bar magnet
is an artificial magnet. This
type of magnets are usually made from a combination
of elements that contain
iron, cobalt or nickel.
3. Iron does not always behave like a magnet and this is because its atoms are usually disorganised. A needle, for example, that contains iron is not a magnet (A) but when you rub the needle with a magnet, its atoms line up and the needle becomes a magnet (B). The needle can then attract other metals. This property of some substances to attract metals is called magnetism.
4. Electromagnetism and gravity are two basic forces of nature. They are very similar and scientists are trying to unify them. Electromagnetism works in small objects – it attracts the electrons from the atomic nucleus and maintains them in place. Gravity works with big objects – the pull of gravity from the nucleus of the Earth maintains our atmosphere in place. Both, the electrons and the Earth, spin and generate an electric and a magnetic field around them. These fields make up our planet’s electromagnetic shield.
Vocabulary
IV. Remember these words:
property, to generate, needle, bar, point, to maintain, charge, iron, to attract, field.
Grammar
V. Look for words in the text derived from the nouns below. Identify, if it’s a noun or an adjective.
Example: gravity – gravitational (adj.)
1. Magnet ________
2. Atom ________
3. Geography ________
4. Electron ________
5. Sphere ________
VI. From the words given below form adjectives using the following suffixes:
a) -able
to change, to consider, to suit, to move, to compare, to control, to represent;
b) -ous
danger, advantage, to vary, to continue;
c) -less
doubt, form, wire, regard, use, help, hope;
d) -al
industry, centre, culture, form, nation, mechanics.
VII. Translate the following words and define the meaning of their prefixes:
disproportional, indifferent, impossible, to reheat, preheat, overload, to miscalculate, reaction, to misunderstand, irregular, dissimilar, supercritical, undoubtedly, impractical, disproportional, misdirection, immeasurable.
