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The same milliammeter can of course be used for measuring
currents up to 1mA by connecting it in series in the current path; but
to avoid increasing the resistance of the circuit more than need be,
the voltage resistances would have to be short-circuited or otherwise
cut out. Care must be taken never to connect a current meter directly
across a voltage source, for its low resistance might pass sufficient
current to destroy it. Higher currents can be measured by diverting
all but a known fraction of the current through a bypass resistance
called a shunt. If, for example, the resistance of the 0—1
milliammeter is 75Ω, shunting it with 75/