Objective: To measure the least counts and percent errors
Introduction:
Experimental errors are generally categorized in two types: random and systematic error. Random or statistical errors resulting from uncertain and unpredictable variances occur in every experimental circumstance whereas systematic errors result from inaccurately calibrated equipment or because of the bias of the observer to note values.
The least count error occurs with both systematic and random errors. Least count of the instrument scale is the smallest subdivision on the measurement scale. For instance, the least count of a meter ruler is millimeter. Lower the least count there is a low chance for error. Percentage error is calculated for a comparison of an experimental value with the accepted value.
Instruments:
Meter rule
Decimeter calibrated meter rule
Centimeter calibrated rule
Millimeter calibrated meter rule
Procedure and Observation:
We used a meter rule, a decimeter-calibrated meter rule, a centimeter-calibrated rule, and a millimeter-calibrated meter rule to measure a metal rod. The actual length was provided by the instructor. The measurements were noted, and each ruler's % error was computed.
Data and Calculations:
Measured length,
In meter = 0.9 m
In decimeter = 8.9 dm
In centimeter = 88.7 cm
In millimeter = 889.0 mm
Actual length provided by instructor = 91.20 cm
Percent error = (|Experimented value - Actual value| / Actual value) * 100%
Experimental Error and Data Analysis
Objective: To measure the least counts and percent errors
Introduction:
Experimental errors are generally categorized in two types: random and systematic error. Random or statistical errors resulting from uncertain and unpredictable variances occur in every experimental circumstance whereas systematic errors result from inaccurately calibrated equipment or because of the bias of the observer to note values.
The least count error occurs with both systematic and random errors. Least count of the instrument scale is the smallest subdivision on the measurement scale. For instance, the least count of a meter ruler is millimeter. Lower the least count there is a low chance for error. Percentage error is calculated for a comparison of an experimental value with the accepted value.
Instruments:
Procedure and Observation: We used a meter rule, a decimeter-calibrated meter rule, a centimeter-calibrated rule, and a millimeter-calibrated meter rule to measure a metal rod. The actual length was provided by the instructor. The measurements were noted, and each ruler's % error was computed.
Data and Calculations:
Measured length,
In meter = 0.9 m
In decimeter = 8.9 dm
In centimeter = 88.7 cm
In millimeter = 889.0 mm
Actual length provided by instructor = 91.20 cm
Percent error = (|Experimented value - Actual value| / Actual value) * 100%
Percent error in meter = |0.9 - 0.912| / 0.912 * 100% = 1.3%
Percent error in decimeter = |8.9 - 9.12| / 9.12 * 100% = 2.4%
Percent error in centimeter = |88.7 - 91.20| / 91.20 * 100% = 2.7%
Percent error in millimeter = |889 - 912| / 912 * 100% = 2.5%
Conclusion: Percent error is less in meters and it is high in centimeter reading. Instruments of higher precision can reduce the least count error.