Basic ohmmeter use  Question 1  Explain how an ohmmeter is able
to measure the resistance of a component (in this case, a light
bulb) when there is no battery or other source of power
connected to it:  Also, identify the reading you would expect
the ohmmeter to indicate if the light bulb were burnt out
(failed öpen").  Ohmmeters always contain a battery or some
other internal source of electrical power so that the component
under test may be supplied with a small amount of current, in
order to measure how hard it is for current to go through. If
the light bulb were burnt open, the ohmmeter would register an
extremely large (infinite) amount of resistance.  Unlike
voltmeters or ammeters, ohmmeters must contain their own power
sources. An implication of this fact is that ohmmeters must
never be used to measure the resistance of an energized
component. Discuss this important caveat with your students,
being sure to ask them to explain why connecting an ohmmeter to
an energized component might give erroneous meas