Facts about experimental error
1.
Measurement
errors mean deviation from actual result.
2.
Error
in interpretation occur because some factors considered negligible may not be
negligible.
3.
No
matter how precise an experiment may be, values interpreted may be incorrect
because some theories are over-idealized.
4.
Error
in measurement occurs because some tools may alter the value of parameter to be
measured.
5.
Inappropriate tools of measurement tools may
cause experimental errors.
6.
Error
can be classified into random, erratic and systematic error.
7.
Measurement
at atomic level is limited due to the facts that small interaction can alter
the whole system.
8.
It
is advisable to use potentiometer to measure circuit p.d instead of voltmeter.
9.
A
micrometer screw gauge may alter the diameter of thin wire when used.
10.
Error
should be look and corrected except where it is practically impossible.
11.
Wrong
calibration of scale can lead to error.
12.
Error
due to calibrations of scale can be corrected by addition or subtraction.
13.
It
is advisable to use travelling microscope to measure diameter of thin wire.
14.
Experimental
error can be corrected by adding, subtracting multiplying or dividing by a
whole number or fraction.
15.
Wrong
use of value of standards can lead to lead to overall increase or decrease in
final result , that’s a systematic error
16.
Faults
in instrument can lead to recurring error in the measurement, that’s a
systematic error.
17.
Systematic
error increase or decrease the overall value.
18.
Using
alternative method or instrument can reduce error.
19.
Comparing
measured value with theoretically predicted values can help check experimental
error.
20.
Random
errors are difficult to eliminate because they occur irregularly.
21.
Inhomogeneity
of materials measured can lead o random error.
22.
Irregularities
in shape of materials can lead to error.
23.
Random error seems to be systematic in a
sufficiently large number of readings.
24.
Erratic
errors are accidental errors that occur once in a while.
25.
Erratic
errors occur due one or two mistake in the cause of the experiment.
26.
Erratic
errors are not always common in an experiment.
27.
Erratic
errors are mostly very large.
28.
Large
electrical or magnetic interference can cause erratic error.
29.
Miscounting
of period of pendulum oscillation, arithmetical mistake can cause erratic.
30.
Faulty
electrical contacts can lead to error.
31.
Accuracy
of measurement means closeness to exact value.
32.
Accuracy
means absent of systematic error
33.
Precision
of measurement means absence of random and erratic error.
34.
No
systematic error means reliability of experiment final result.
35.
No
random and erratic error means reliability of measurement method.
36.
The
closeness of experiment result to exact value is a measure of accuracy.
37.
The
standard of experiment is a measure of the precision of the techniques of
measurement.
38.
Experimental
errors can be represented as either estimated standard or maximum error.
39.
Estimated
maximum error gives the outside value an error will lie.
40.
Maximum
error gives two values one very high and one very low.
41.
Standard
error is the root mean square error that will occur in large number of
measurement.
42.
Random
error varies from one measurement to another.
43.
Miscounting
of number of oscillation of a pendulum can lead to erratic error.
44.
Erratic
errors are easy to correct.
45.
Repeating
measurement and using alternate tools can help check error.
46.
Difference
between two measured values are said to be significant if their difference is
greater than the sum of their standard error.
47.
Ensure
all precautions are taken
48.
In
experiment involving pendulum ensure that air resistance are checked
49.
Environmental
factors like temperature may affect measurement.
50.
Always
re-zero instrument before using them.
51.
Ensure
all pointing instrument are stable and at equilibrium before taking your readings.
E.g. thermometer.
52.
Misreading
a scale, forgetting a digit in reading, recording wrong values amount to
erratic error.
53.
Random
errors are caused by unknown and unpredictable change in experiment.
54.
Avoid
zero setting error by ensuring instrument measures zero point when quantity
measures zero.
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