Department of Pre-University Education, KarnatakaPUC Karnataka Science Class 11

# The Radius of a Circle is Stated as 2.12 Cm. Its Area Should Be Written as - Physics

MCQ

The radius of a circle is stated as 2.12 cm. Its area should be written as

• 14 cm2

• 14.1 cm2

• 14.11 cm2

• 14.1124 cm2

#### Solution

14.1 cm2

Area of a circle, A=  $\pi r^2$ On putting the values, we get:

$A = \frac{22}{7} \times 2 . 12 \times 2 . 12$

$\Rightarrow A = 14 . 1 {cm}^2$

The rules to determine the number of significant digits says that in the multiplication of two or more numbers, the number of significant digits in the answer should be equal to that of the number with the minimum number of significant digits. Here, 2.12 cm has a minimum of three significant digits. So, the answer must be written in three significant digits.

Concept: What is Physics?
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#### APPEARS IN

HC Verma Class 11, Class 12 Concepts of Physics Vol. 1
Chapter 2 Physics and Mathematics
MCQ | Q 6 | Page 28
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