A circular wire of radius 7 cm is cut and bend again into an arc of a circle of radius 12 cm. The angle subtended by the arc at the centre is

Question

A circular wire of radius 7 cm is cut and bend again into an arc of a circle of radius 12 cm. The angle subtended by the arc at the centre is (A) 50° (B) 210° (C) 100° (D) 60°

Tardigrade Admin · Accepted Answer

Circumference of a circular wire of radius 7 cm =2π × 7 = 14 π As we know θ=(l/r) ⇒ θ=(14π/12) =(7π × 180°/6π)=210°.

Q. A circular wire of radius $7 c m$ is cut and bend again into an arc of a circle of radius $12 c m$ . The angle subtended by the arc at the centre is

$5 0^{\circ}$

$21 0^{\circ}$

$10 0^{\circ}$

$6 0^{\circ}$

Circumference of a circular wire of radius $7 c m$
$= 2 π \times 7 = 14 π$
As we know $θ = \frac{l}{r}$
$\Rightarrow θ = \frac{14 π}{12}$
$= \frac{7 π \times 18 0 ^{\circ}}{6 π} = 21 0^{\circ}$ .

Q. A circular wire of radius 7cm is cut and bend again into an arc of a circle of radius 12cm. The angle subtended by the arc at the centre is

50∘

210∘

100∘

60∘