Consider the following statements: 1. If the volume of a cylinder is 5π times the cube of its diameter, then the height of the cylinder is 20 times its radius. 2. If the curved surface area of a cylinder is 4π times the square of its diameter, then the height of the cylinder is 8 times its radius. Which of the above statements is/are correct?
Consider the following statements: 1. If the volume of a cylinder is 5π times the cube of its diameter, then the height of the cylinder is 20 times its radius. 2. If the curved surface area of a cylinder is 4π times the square of its diameter, then the height of the cylinder is 8 times its radius. Which of the above statements is/are correct? Correct Answer 2 only
Let the height and the radius of the cylinder be ‘h’ units and ‘r’ units respectively
Considering statement 1,
Volume of cylinder = 5π × (diameter)3
⇒ πr2h = 5π × (2r)3
⇒ πr2h = 5π × 8r3
⇒ h = 5 × 8r
⇒ h = 40r
Statement 1 is not correct
Considering statement 2,
Curved surface area of cylinder = 4π × (diameter)2
⇒ 2πrh = 4π × (2r)2
⇒ 2πrh = 4π × 4r2
⇒ h = 4 × 2r
⇒ h = 8r
Statement 2 is correct
∴ Only statement 2 is correct