Question

Find the ratio of heights of two cylinders, if volume of two cylinders are equal and radius of two cylinders are in the ratio 2 : 1.
1. 1 : 4
2. 2 : 4
3. 5 : 6
4. 9 : 7

Answer 1

Correct Answer - Option 1 : 1 : 4

Given

Radius of two cylinders = 2 : 1

Volume of two cylinders are equal

Formula used

Volume of cylinders = πr²h

Where r and h are radius and height of cylinders respectively

R/r = 2/1

Calculation

πR²h = πr²H

Where R, h, r and H are radius and height of two cylinders respectively 

R²/r² = H/h

(2/1)² = H/h

4/1 = H/h

h/H = 1/4

h : H = 1 : 4

The ratio of heights of two cylinders is 1 : 4