Video Transcript
In an experiment, three
measurements are taken. Which of the three measurements
represents resistance? Is it (A) measurement one, (B)
measurement two, or (C) measurement three?
This question asks us about an
experiment where three measurements are taken as we can see in the table. All three measurements have the
same value of one, but each measurement is of a different quantity. We can see that the measurements
are of different quantities as they have different unit symbols written after their
values, 𝛺, A, and V.
The question asks, which
measurement was a measurement of the quantity rsistance? To answer this, we need to know
what the unit symbol for the unit resistance is. Recognizing this unit symbol will
be easier if we remember the name of the unit of resistance. The unit of resistance is the
ohm. The ohm is named after Georg Ohm
who defined resistance. We may be wondering why there is no
measurement that is written one O, where we might expect to see O stand for
ohms. It so happens that there is a Greek
letter called 𝛺, and uppercase 𝛺 is as shown. An 𝛺 is used to stand for ohms
rather than an O.
One reason why it would probably be
a bad idea to use O for a unit symbol is that O is easily mistaken for the numeral
zero. Somebody could mistake a
measurement of one O for the value 10. It is much less likely that someone
would mistake one 𝛺 for 10.
Anyway, the correct answer is one
ohm written one 𝛺. Option (A), measurement one, is
correct.
