Question

Which of the following quantities has smallest number of significant digits ?

• A. $0.00145\text{cm}$
• B. $14.50\text{cm}$
• C. $145.00\text{cm}$
• D. $145.0\times {10}^{-6}\text{cm}$

Answer 1

The correct option is A $0.00145\text{cm}$

In option (a), there are 3 significant digits, since the preceding zeros are not to be counted.

While in rest of the options, there are 4 significant digits since the trailing zeros are counted.