Question 11/99
OHM'S LAW
Nowadays high school and university students use voltmeters
and ammeters to demonstrate Ohm's law. These devices were not
available in Ohm's time! (Moreover, these devices rely on laws (including
Ohm's law) not known at the time.) How did Ohm do it? Suggest experiments
(using only equipment available in 1826, or similar present-day equipment)
showing that:
(a) "voltage" is proportional to "current";
(b) for fixed "voltage", the "current" is proportional to the cross-sectional area of the wire
and inversely proportional to its length.
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