Question

The respective number of significant figures for the numbers $23.023$, $0.0003$ and $2.1\times 10^{-3}$ are

• A. $5$, $1$, $2$
• B. $5$, $1$, $5$
• C. $5$, $5$, $2$
• D. $4$, $4$, $2$

Answer 1

Answer: (A)

Rule : I. All non zero digits are significant.
Rule : II. If zero is between two non-zero digits, then it is also significant.
Rule : III. If zero left to the non-zero digit, then it is non significant. Significant figures for number $23.023$ is $5$ (Using $I$ and $II$ Significant figures for number $0.0003$ is $1$ (Using $I$, $II$ and $III$).
Significant figures for number $2.1\times 10^{-3}$ is $2$ (Using $I$).