Question

'Sup people!

If the true value of a measurement is 3.678 and the values measured by two different measurement devices are 3.6 and 3.65 respectively.

Then which value is accurate and which is precised?


Class 11th
Units and Measurement
A fully sure answer!
Thanks =]
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Answer 1

Answer : 3.65 is precise and 3.6 is accurate.

Explanation :

Accuracy : The accuracy olof a measurement indicates the extent to which an experimentlly measured value is close to the true value.

Accuracy = Mean experiment value - True value..

Smaller the difference between mean experiment value and true value,greater is its accuracy.

Precision : The term precision refers to closeness of the values of different measurements of a quantity.

When the values of different neasurements are close to each other and hence close to their average value, the measurement is said be precise

Example :

Suppose three students A,B and C were asked to weigh a metal coin whose actual mass is 10.1564g

The data obtained by each student were :

Student A

- 10.1572 (1)

- 10.1568 (2)

- 10.1570 (3)

- 10.1574 (4)

= 10.1571 ( average)

Student B

- 10.1568 (1)

- 10.1566 (2)

- 10.1562 (3)

- 10.1566 (4)

= 10.1565 ( average)

Student C

- 10.1566 (1)

- 10.1564 (2)

- 10.1564 (3)

- 10.1564 (4)

= 10.1564 (average)

Obivously, The data obtained by student A are neither precise nor accurate, on the other hand

measurement carried by student B is precise.

(average not accurate)

measurement carried by student C is both precise and accurate.