2016 · Q49
A truck moves along a circular path and describes 100 m when it has traced out 36° at the centre. The radius of the circle is equal to
Elementary MathematicsCircles
- A100/π m
- B250/π m
- C500/π m
- D600/π m
Explanation
Arc length follows l = rθ with θ in radians. Convert 36° to radians: 36° = 36π/180 = π/5. Substituting the given arc length: 100 = r × π/5. Solving, r = 100 × 5/π = 500/π m. The radian conversion is the crux — using degrees directly would give a wrong numerical value. Hence option (C) 500/π m.