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Exploring materials which cause a decrease in deflection when added in series with our meter.
Why does the deflection change when an electromagnet is attached to the circuit? Does it matter what side of the electromagnet we test?
A pencil causes a change in the deflection, similar to the effect of adding an electromagnet. Why?
We use the inside of a pencil (graphite) to apply different "lengths of pencil" to the circuit. What relationship do you observe between length of graphite and deflection angle?
Here we draw a line on a page and use it as a variable resistor in series with a speaker. What relationship do we hear? Does it sound linear?