When it has been determined that the voltage to a unit is approximately 115 volts, which range should an analogue meter be set at to achieve the most accurate reading?

When it has been determined that the voltage to a unit is approximately 115 volts, which range should an analogue meter be set at to achieve the most accurate reading?

• A. 0-100 volts
• B. 0-150 volts
• C. 0-250 volts
• D. 0-500 volts

Answer: (B)

The most accurate reading on an analogue meter occurs when the measured voltage falls within the middle range of the meter's scale. In this case, a unit voltage of approximately 115 volts is being tested. Setting the analogue meter to a range of 0-150 volts allows the measurement to be taken close to the center of that scale, typically offering improved accuracy and resolution. When a meter is configured to a range that is too low, like 0-100 volts, it may lead to a reading that is at the upper limit of that scale, resulting in a less precise measurement.

On the other hand, setting the meter to a significantly higher range, such as 0-250 volts or 0-500 volts, while still permitting the measurement, can lead to decreased accuracy. This is because the reading is then taken farther from the center of the scale, reducing the sensitivity and resolution of the measurement. Hence, choosing the 0-150 volts range strikes the right balance, delivering a precise reading for the measured voltage of approximately 115 volts.