Question

The mean length of an object is $5cm$. Which of the following measurements is most accurate?

• A. $4.9cm$
• B. $4.805cm$
• C. $5.25m$
• D. $5.4cm$

Answer 1

The correct option is A $4.9cm$

Accuracy describes the nearness of a measurement to the standard or true value, i.e. a highly accurate measuring device will provide measurements very close to the standard, true or known values.
Example: In target shooting, a high score indicates the nearness to the bull’s eye and is a measure of the shooter’s accuracy.

According to the problem,length $l=5cm$

Let us first check the errors in each values by picking options one by one, we get,

$\Delta l_1=5-4.9=0.1cm,\Delta l_2=5-4.805=0.195cm,$

$\Delta l_3=5.25-5=0.25cm$ and $\Delta l_4=5.4-5=0.4cm$
Error $\Delta l_1$ is the least.

Hence $4.9cm$ is most closer to true value.So, $4.9$ is more accurate.