If the numerical value of the volume and the curved surface area of a right circular cone are equal, then the diameter of the cone is **4 units**. --- Let the radius be \(r\). Then, volume \(= πr^2h\) and curved surface area \(= 2πrh\) So, \(πr^2h = 2πrh\) ⇒ \(r = 2\) ∴ Diameter \(= 2 × 2 = 4\) units.