WHAT IS SIGNIFICANT FIGURES AND WHAT ARE THE USES ?

RAHUL RANJAN, 13 years ago

Grade:11

3 Answers

SAGAR SINGH - IIT DELHI

878 Points

13 years ago

Dear rahul,

Every measurement has a degree of uncertainty associated with it. The uncertainty derives from the measuring device and from the skill of the person doing the measuring. Let's use volume measurement as an example. Say you are in a chemistry lab and need 7 mL of water. You could take an unmarked coffee cup and add water until you think you have about 7 milliliters. In this case, the majority of the measurement error is associated with the skill of the person doing the measuring. You could use a beaker, marked in 5 mL increments. With the beaker, you could easily obtain a volume between 5 and 10 mL, probably close to 7 mL, give or take 1 mL. If you used a pipette marked to with 0.1 mL, you could get a volume between 6.99 and 7.01 mL pretty reliably. It would be untrue to report that you measured 7.000 mL using any of these devices, because you didn't measure the volume to the nearest microliter. You would report your measurement using significant figures. These include all of the digits you know for certain plus the last digit, which contains some uncertainty.

We are all IITians and here to help you in your IIT JEE preparation.

All the best.

If you like this answer please approve it....

win exciting gifts by answering the questions on Discussion Forum

Sagar Singh

B.Tech IIT Delhi

Aniket Patra

48 Points

13 years ago

To be very general u can say them approximation.They are used to figure out a single whole number nearest to it such that the error in counting is least.