Final answer:
Electrical gauges like voltmeters and ammeters require careful calibration with resistors to provide accurate readings and are limited in sensitivity. Their inaccuracies are typically due to alterations in the circuit caused by the meter, not the meter itself. Digital meters offer higher accuracy, especially for low voltage measurements.
Step-by-step explanation:
Many electrical gauges, such as voltmeters and ammeters, are designed with practical limits on their sensitivity. For accuracy, these analog meters are typically used with a combination of a resistor and a galvanometer. To address various voltage ranges, adjustable resistances are placed in series with the galvanometer to allow for different meter scales. While these meters can be accurate to within a few percent, it is important to note that any inaccuracy generally arises from how the meter alters the circuit, rather than being an intrinsic fault of the meter itself.
Digital meters, which are capable of detecting smaller currents, can often measure voltage and current more accurately than their analog counterparts due to their ability to detect finer changes without significantly altering the circuit being measured. In the case of a voltmeter, for voltages less than about half a volt, the meter deflection would be too small to read accurately; therefore, for low voltages, digital meters are preferred.