Question

Assertion:
The precision of a measurement depends on the least count of measuring instruments.
Reason:
The smaller the least count greater is the number of significant figures in measurement value.
(A) Both assertion and reason are correct and the reason is the correct explanation for the assertion.
(B) Both assertion and reason are correct but the reason is not the correct explanation for the assertion.
(C) assertion is correct but reason is incorrect.
(D) Both assertion and reason are incorrect.

Answer 1

Hint: We know that the Least count is the minimum or the smallest measurement taken by a measuring instrument, we also know that the smaller the least count of the instrument greater the accuracy in the measured value.

Complete step by step answer:
 The least count is the minimum or the smallest measurement taken by a measuring instrument. The least count is related to the precision of an instrument, the least the least count the more accurate will be the result. We can say that accuracy is the ability to measure the closer value to the exact value. We can measure anything with more accuracy with the instrument having a smaller least count. Thus, we use vernier caliper in place of a normal scale to measure the length more accurately.
The least count of the normal scale is 1mm whereas the least count of vernier calliper is 0.01 mm. We know that \[0.01mm < 1mm\] means the vernier calliper will give us more accurate measurements as compared to a normal scale.
Based on this fact the small least count gives us more accurate measurement. We can say that the precision of a measurement depends on the least count of the measuring instrument also this is because the smaller the least count greater is the number of significant figures in measurement value.
It means both assertion and reason are correct and the reason is the correct explanation for the assertion.

Therefore, option C is correct.

Additional information:
The least normal scale is \[1mm\], the least count of vernier callipers is 0.01 mm. The least count of \[{10^{ - 3}}cm\]. It is Note:d that the smaller the least count of instruments greater the accuracy in the measured value.

Note:
One can think that if the significant number increases in measurement the chances of error will also increase and this will give the wrong measurement. But it is Note:d that the increased insignificant number will give us more accurate values to explain the small length we have considered vernier callipers in place of normal scale because the significant number in vernier callipers is more and we will get more precise value.