# What is the relationship between the accuracy and uncertainty of a measurement?

Question
Measurement
What is the relationship between the accuracy and uncertainty of a measurement?

2021-02-27
Step 1
Accuracy of a measured value refers to how close the measurement is to the correct value. The uncertainty in a measurement is an estimate of the amount by which the measurement result may differ from this value.
Step 2
Generally, uncertainty is given as a percentage. The uncertainty of a measurement is related to the degree of accuracy of the experimental results. In other words, the uncertainty depends on how accurate is an experimental measurement. A high accuracy of an experimental result can be traduced as a lower value of uncertainty and vice versa.

### Relevant Questions

A certain scale has an uncertainty of 3 g and a bias of 2 g. a) A single measurement is made on this scale. What are the bias and uncertainty in this measurement? b) Four independent measurements are made on this scale. What are the bias and uncertainty in the average of these measurements? c) Four hundred independent measurements are made on this scale. What are the bias and uncertainty in the average of these measurements? d) As more measurements are made, does the uncertainty get smaller, get larger, or stay the same? e) As more measurements are made, does the bias get smaller, get larger, or stay the same?
A certain scale has an uncertainty of 3 g and a bias of 2 g.
a) A single measurement is made on this scale. What are the bias and uncertainty in this measurement?
b) Four independent measurements are made on this scale. What are the bias and uncertainty in the average of these measurements? c) Four hundred independent measurements are made on this scale. What are the bias and uncertainty in the average of these measurements?
d) As more measurements are made, does the uncertainty get smaller, get larger, or stay the same?
e) As more measurements are made, does the bias get smaller, get larger, or stay the same?
(Measure the longest dimension of the room twice, using two different techniques. Do the measurement in feet and inches. Then convert to meters.) Below is what I got.
$$Tape Measure - 146 inches > 3.7084 meters / 12 feet and 2 inches = 12.1667 feet > 3.70840 meters$$
$$Ruler - 144.5 inches (144 + 1/2) = 3.6703 meters / 12.0416 feet = 3.67027 meters$$
Why can a null measurement be more accurate than one using standard voltmeters and ammeters?
What factors limit the accuracy of null measurements?
The weight of an object is given as $$67.2 \pm 0.3g$$. True or false:
a) The weight was measured to be 67.2 g.
b) The true weight of the object is 67.2 g.
c) The bias in the measurement is 0.3 g.
d) The uncertainty in the measurement is 0.3 g.
Suppose that the current measurements in a strip of wire are assumed to follow a normal distribution with a mean of 10 milliamperes and a standard deviation of 2 milliamperes.
What is the probability that a measurement exceeds 13 milliamperes? What is the probability that a current measurement is between 9 and 11 milliamperes.
Standard deviation is an indication of the...
a. precision of one measurement
b. accuracy of one measurement.
c. precision of repeated measurements.
a) According to Chebyshev's theorem, at least $$?36\% 56\% 75\% 84\%\ or\ 89\%$$ of the measurements lie between 122.8 mmHg and 143.2 mmHg.
b) According to Chebyshev's theorem, at least $$8/9 (about\ 89\%)$$ of the measurements lie between mmHg and mmHg. (Round your answer to 1 decimal place.)