Extending the Range of Ammeters and Voltmeters The ranges of electrical measuring instruments (whether ammeter, voltmeter or any other type of meters) are limited by the currents, which be carried by the coils of the instruments safely. For example, the moving coils of the instruments can carry maximum current of about 50 mA safely and the potential drop across the moving coil is about 50 mV. Hence, it becomes necessary that the current and voltage being measured be reduced and brought within the range of instrument. There are four common devices used for extending the range of the instruments, namely \ 1. Shunts 2. Multipliers 3. Current transformers 4. Potential transformers The let us discuss the first two topics i.e. shunts and multipliers 1. Shunts: The range of an ammeters can be extended by connect...