Basic HTML Version
34
SECTION 1
CLIL Expansion
Battery
Average price
Duration
Cost per hour
1.
2.
3.
How electricity entered our lives…
T
he discovery of electricity, of its properties and, later, of its seemingly infinite uses and applications has completely
changed people’s lives: it is hard to imagine what daily life would be like today without it!
A century ago, electronics was completely unknown: there were no radios, televisions, computers, robots or artificial
satellites and none of the other products and services that we now take for granted.
Electricity was already known to the Greeks over 2,000 years ago, indeed many ancient cultures around the Mediterranean
knew that certain objects, such as amber rods
1
, could be rubbed with cat’s fur
2
to attract light objects like feathers
3
even
though they did not know why.
Thales of Miletus made a series of observations regarding static electricity around 600 BC, but he believed that friction
was making the amber magnetic, making it behave like some minerals did, such as magnetite, which needed no rubbing.
However electricity/magnetism remained little more than an intellectual curiosity for another 2 millennia until, around
1600 AD, scientists began to study electricity and magnetism more closely.
But until the end of the 18th century the only way they found of making electricity was by friction and this static
electricity only produced very low currents, which could only last for a short time.
The first battery, one which could maintain a current for a longer time, was made by Alessandro Volta in about 1790. In
Volta’s battery the electric current comes from the reaction between chemicals.
It was a pile of silver and zinc discs separated by cloth soaked
4
in salt solution.
1
amber rod
: a “stick” of amber
2
rubbed with cat’s fur
: to create fiction and heat/energy
3
feathers
: are very light
4
soaked
: very wet, impregnated with something
The History of Electricity
TASK 1
Brainstorming
about batteries:
a
Look up the meaning of
battery
in a dictionary.
b
Do you know who invented the battery?
c
Do you know how many types of battery there are today?
d
What are the differences between different types of battery?
e
What is a rechargeable battery? How does it work?
f
Complete the chart below, listing the items required. Follow the guidelines.
And now:
a
Compare a selection of different 1.5 V batteries of the same size and note their prices.
b
Devise an ex-
periment to test how long each battery will last and note the results.
c
Work out the cost of running
each battery for one hour and find out which battery is best value for money
TASK 2
a) Read this text and draw up a timeline of discoveries, inventions and innovations concerning electricity.
CLIL
with
History
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Progetto FOR ELECTRONICS_unit_1.indd 34
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