Tag: accuracy, precision and uncertainty in measurement

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Questions Related to accuracy, precision and uncertainty in measurement

Multiple choice physics units and measurement: error analysis accuracy of measurement accuracy and precision accuracy, precision and uncertainty in measurement

If we weigh a given substance five times, and get 5 kg each time, then your measurement is very __________.

  1. Accurate

  2. Precised

  3. Accurate and Precised

  4. Cannot be judged
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Accuracy is defined as the extent upto which a given measurement agrees with the standard value for that measurement whereas the degree to which several measurement provide answer very close to each other is known as precision.
Since the measured values are very close to each other, then the measurements are said to be precised.

Multiple choice physics units and measurement: error analysis accuracy of measurement accuracy and precision accuracy, precision and uncertainty in measurement

The degree to which several measurement provide answer very close to each other is known as:

  1. Accuracy

  2. Precision

  3. Accuracy and Precision

  4. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The degree to which several measurement provide answer very close to each other is known as precision.For example : Let the true weight of given substance is 12 kg.
The values of three measurements obtained by student are 10.1, 10.2 and 10.3. Then the measurements are said to be precise.

Multiple choice physics units and measurement: error analysis accuracy of measurement accuracy and precision accuracy, precision and uncertainty in measurement

Accuracy of potentiometer can be easily increased by :

  1. increasing resistance of wire

  2. decreasing resistance of wire

  3. increasing the length of wire

  4. decreasing the length of wire
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Accuracy of potentiometer can be easily increased by decreasing the potential gradient across the potentiometer wire and that can be done by increasing its length.

Multiple choice physics units and measurement: error analysis accuracy of measurement accuracy and precision accuracy, precision and uncertainty in measurement

________ reflects quality of measuring instrument.

  1. Precision

  2. Accuracy

  3. Accuracy and Precision

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The degree to which several measurement provide answer very close to each other is known as precision. In other words, precision reflects the quality of measuring instrument.

Multiple choice physics units and measurement: error analysis accuracy of measurement accuracy and precision accuracy, precision and uncertainty in measurement

In the context of accuracy to measurement and significant figures in expressing results of experiment, which of the following is/are correct?
(1) Out of the measurements 50.14 cm and 0.00025 ampere, the first one has greater accuracy.
(2) If one travels 478 km by rail and 397 m. by road, the total distance traveled is 478 km.

  1. Only (1) is correct

  2. Only (2) is correct

  3. Both are correct

  4. None of these is correct.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Since for $50.14cm$
Now, the significant number$=4$
and for$0.00025$
Significant number $=2$
Both are correct
Multiple choice physics units and measurement: error analysis accuracy of measurement accuracy and precision accuracy, precision and uncertainty in measurement

Find the maximum possible percentage error in the measurement of force on an object(on mass m) travelling at velocity v in a circle of radius r, if m=(4.0 plus minus 0.1)kg, v=(10 plus minus 0.1)m/s and r=(8.0 plus minus 0.2)m

  1. ( 50&nbsp;<span>± 1) N</span>

  2. <span>( 50&nbsp;</span><span>± 2.5) N</span>

  3. <span>( 50&nbsp;</span><span>± 1.5) N</span>

  4. <span>( 50&nbsp;</span><span>± 3.5) N</span>
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Force$(f)=\cfrac{mv^2}{r}=\cfrac{4\times(10)^2}{8}=50\ \therefore\cfrac{\Delta F}{F}=\cfrac{\Delta m}{m}+2(\cfrac{\Delta V}{V})+(\cfrac{\Delta r}{r})\ \quad=\cfrac{0.1}{4}+2\cfrac{(0.1)}{10}+\cfrac{0.8}{8}\ \therefore \cfrac{\Delta F}{F}=0.07$

Percentage error in $F=25\%+2+2.5\%$
$\therefore$ Percentage error in $F=7\%$
Eror in $\Delta F$ in $F=F\times0.07\ \quad=0\times0.07$
$\therefore$ Error in $\Delta F$ in $F=3.5N$
$\therefore F=(50\pm3.5)N$

Multiple choice physics units and measurement: error analysis accuracy of measurement accuracy and precision accuracy, precision and uncertainty in measurement

The accuracy in the measurement of the diametre of a hydrogen atom as ${ 1.06\times 10 }^{ -10 }$ m is

  1. $0.01$

  2. ${ 106\times 10 }^{ -10 }$

  3. $\dfrac { 1 }{ 106 } $

  4. ${ 0.01\times 10 }^{ -10 }$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Accuracy refers to how close a measurement is to the true value. The relative error is the absolute error divided by the measured value. Here, the precision is 0.01, so the accuracy is 0.01 / 1.06.

Multiple choice physics units and measurement: error analysis accuracy of measurement accuracy and precision accuracy, precision and uncertainty in measurement

Out of the following the more precise value is .....

  1. $1.200 \times 10 ^ { 3 } k m$

  2. $1.20 \times 10 ^ { 3 } k m$

  3. $1.2 \times 10 ^ { 3 } k m$

  4. $1200 k m$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Precision is determined by the number of significant figures. 1.200 x 10^3 has four significant figures, which is more precise than the other options provided.