Kopiervorlage
Worksheet: From an observation to an explanation of our experiment
How do we get from a first observation in an experiment to a useful explanation?
This gap text shows you how. However, it is up to you to find the right solutions …
Two light bulbs in an electric circuit
We have added a second light bulb to an electric circuit that already had one light
bulb. We placed this second light bulb either in front of or behind the first one. Our
observation was: both lamps have ______________ brightness1 (approximately2).
This is not a big surprise for us, because the same ______________ has to go through
both light bulbs.
Besides, the use of a second light bulb – with constant generator rotation speed – had
as a result that both light bulbs were shining _____________ brightly than a single
bulb in the same circuit. At the same time, turning the generator had become
_____________ than before. Both observations lead to only one conclusion: with
two light bulbs and at the same speed of generator rotation, there is ______________
than with one light bulb.
Why is this the case3? We already know: the bigger the ______________________
that the current has to pass, the _______________________ is the current. In this
way, electrical devices4 (with different _________________ inside) control the current flowing through them and through this also their ______________________
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intake. If the use of two bulbs in a series connection in one circuit causes less
_________________________, then the reason for this has to be that two light bulbs
cause twice the _________________as one. There is less ____________________
flowing and therefore also less power, so the two bulbs shine less brightly.
1 describes how bright sth. is (Helligkeit)
2 about (ungefähr)
3 a fact we can observe (to be the case – der Fall sein)
4 small machines are called devices (Gerät)
112 Physik – der Exot unter den bilingualen Fächern
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