Question

A circular wire of diameter 10cm is cut and placed along the circumference of a circle of diameter 1 metre. The angle subtended by the wire at the centre of the circle is equal to

• A. $\frac{\pi }{4}$ radian
• B. $\frac{\pi }{3}$ radian
• C. $\frac{\pi }{5}$ radian
• D. $\frac{\pi }{10}$ radian

Answer 1

The correct option is C

$\frac{\pi }{5}$ radian

Given, diameter of circular wire = 10cm,
$\therefore$ length of wire = circumference of circle = $10\pi$.

Using $angle=\frac{arc}{radius}=\frac{10\pi }{50}=\frac{\pi }{5}$ radian.