Question

The circumference of a circle is measured as 28 cm with an error of 0.01 cm. The percentage error in the area is

A. \(\frac{1}{14}\)

B. 0.01

C. \(\frac{1}{7}\)

D. None of these

Answer 1

Correct answer is A.

given that circumference is = C = 2πr = 28 cm

That’s mean r = 14/π

ΔC = 2πΔr = 0.01

Δr = (0.01/2π)

We all know that area of a circle is = A = πr²

ΔA = 2πr × dr

So finally,