Chapter 1, Problem 7Q

To determine

The value of diameter.

Answer to Problem 7Q

Solution: The diameter of circle is8.32 cm because the measurement represents 3 significant digits.

Explanation of Solution

Given:

Radius, $r=4.16\text{cm}$

Formula Used:

Diameter, $d=2\times r$

The factor 2, used to calculate diameter is an exact value. Further, it has no uncertainty.

Calculation:

  $\begin{array}{l}d=2\times r\\ d=2\times 4.16\text{cm}\\ d=8.32\text{cm}\end{array}$

The measurement represents 3 significant figures and hence, the result should also be in three significant figures, i.e., 8.32 cm and not 8 cm.

Conclusion: The factor 2, used to calculate diameter is an exact value.It has no uncertainty and so, it does not change the number of significant figures.