Simple measurements and calculations

What the Activity is for

Anchoring quantities in student actions.

Making measurements gives a real connection to the quantities involved.

What to Prepare

• some cells and batteries, 1.5–6 volt
• some electrical wires
• a well-designed ammeter
• a well-designed voltmeter
• a collection of lamps and resistors to match the batteries and meters
• printed copies of the support sheets (see below)

What Happens During this Activity

Introduce a number of circuits where the goal is to find the effective resistance of the circuit. Students need to choose where to put the ammeter and voltmeter, and then transfer their choice and readings to the calculations templates. As with writing templates, the idea here is to encourage good practice and that students should eventually lay out their calculations by themselves. The templates are there to act as prototypes of clear communication.

There are extensions that could be made, from seeing if the resistance stays constant as the potential difference is varied, to finding the resistance of separate components in the circuit. However, no circuits much more complex than these are appropriate at this level.