I saw a new dentist a few weeks ago. I could easily see the x-ray from the
chair, and wrote down some information. I often use "real"
devices/appliances in my classes when discussing electricity, Ohm's Law,
etc.
x-ray machine:
60 kV
7 mA
Using Ohm's Law, we get:
R = (60,000 V)/(0.007 A) = 8.57 x 106 ohms
I thought this result was interesting -- either very high or Ohm's Law
does not apply well in this case. Any ideas?