5 Questions
What is the purpose of adding a shunt resistance in a PMMC instrument used as an ammeter?
To allow measuring large currents without destroying the PMMC wire
What is the total current passing through the ammeter at full-scale deflection (FSD) in the given example?
$0.1 mA$
In a PMMC instrument used as an ammeter, where does most of the measured current pass at full-scale deflection (FSD)?
Through the shunt resistance
What is the purpose of connecting a swamping resistance in series with a PMMC instrument used as an ammeter?
To minimize the effect of temperature change on the PMMC resistance
What happens to a PMMC instrument's coil resistance with temperature changes, and how is this issue addressed?
The coil resistance increases with temperature, and it is addressed by connecting a swamping resistance in series.
Test your knowledge of deflection type ammeters and voltmeters with this quiz covering topics such as DC ammeters, DC voltmeters, AC voltmeters, and AC ammeters. Learn about the PMMC instrument and its use as an ammeter for measuring DC current, as well as the modifications needed for measuring large currents.
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