Question

The number of significant digits in \[0.0045\] is:
(A) two
(B) three
(C) four
(D) Five

Answer 1

Hint: In this question, we will use the concept of the significant figures. As we know that the significant digits are nonzero numbers. Zero is considered as the significant digit when it is in between the two significant digits.

Complete answer:
-As we know that the significant figures are the numbers which often measure the degree of accuracy of the value. The nonzero numbers are the significant numbers. The significant numbers are counted at the first nonzero digits.
-The significant figure is determined by the several rules. All the nonzero numbers are considered to be the significant figures. And when zeros are between the two nonzero numbers then they are the significant figure.
-When the zeros are at the right side of the decimal, then they are taken as the significant figure. And when the number ends with zeros to the left side of the decimal point, they are said to be significant figures.
-In this question, we are given the significant figure \[0.0045\].
-Here, we have the two digits before the numbers. And zeroes are at the left side of the numbers. So, they are not a significant number.
-And we have two non-zero digits \[4\] and \[5\].
-Hence, \[0.0045\] has the two significant digits.

Therefore, option A is correct.

Note:
As we know that if the zeroes which are at the left side of the decimal, they are not said to be the significant digits. All the non zeros numbers are considered as the significant numbers and if the zeros are after the non-zero number then it will be considered as the significant digits.