Calculating Percentage Error in Voltage Measurement

Explanation:

To calculate the percentage error of a measurement, we need two values: the experimental value (the measured value) and the accepted value (the true value). In this case, the experimental value is given as 10.5 V. Let's calculate the percentage error for each measurement method:

(a) VOM with accuracy ±2% and 20 V range:
The range of the VOM is 20 V, which means the maximum error is 2% of 20 V = 0.4 V. Since the measured value is 10.5 V, the percentage error is (0.4 V / 10.5 V) * 100% = 3.81%.

(b) DMM with accuracy ±(0.4% reading +1 digit):
The DMM accuracy is ±(0.4% reading +1 digit). For this calculation, we need to know the number of digits used to display the measurement. Let's assume it's a 3-digit DMM. The percentage error is (0.4% * 10.5 V) + (0.1 V / 10.5 V) * 100% = 0.042% + 0.95% = 0.992%.