Voltmeter Connected to Battery
An analog voltmeter attached to a battery draws a small but nonzero current and measures a terminal voltage that differs from the EMF of the battery. (Note that the script capital E symbolizes electromotive force, or EMF. ) Since the internal resistance of the battery is not known precisely, it is not possible to calculate the EMF precisely.
Source
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"OpenStax College, College Physics. October 26, 2012."
http://cnx.org/content/m42362/latest/?collection=col11406/latest
OpenStax CNX
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