Learner Resource
Ammeters and Voltmeters; why do we put them
where we put them?
Introduction
We have now seen several examples of the use of ammeters and voltmeters, and we can see that
voltmeters always go in parallel and ammeters always go in series. Why?
Clue: how do components in series and in parallel affect the voltage and current in a circuit?
Activity
Learners should be encouraged to ask why we cannot measure amps in parallel or volts in series,
and how we can measure either without noticeably affecting the circuit. In some cases, the word
‘noticeably’ might be important. Knowledge of how voltage and current are affected by components
in series and in parallel should be brought in to the explanation.
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Electric circuits
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© OCR 2015
Extension activities/questions:
Encourage learners to speculate as to how one might create a voltmeter or ammeter and what might
be inside them.
OCR Resources: the small print
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© OCR 2015 - This resource may be freely copied and distributed, as long as the OCR logo and this message remain intact and OCR is acknowledged as the originator of this work:
Page 2: Ammeter and voltmeter, RealVector/Shutterstock.com
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Version 1
Electric circuits
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© OCR 2015