3 Views

Question : The radius of a hemisphere is twice that of a sphere. What is the ratio of the total surface area of the hemisphere and sphere?

Option 1: 3 : 1

Option 2: 12 : 1

Option 3: 4 : 1

Option 4: 6 : 1


Team Careers360 2nd Jan, 2024
Answer (1)
Team Careers360 24th Jan, 2024

Correct Answer: 3 : 1


Solution : The total surface area of a sphere with radius r,
$⇒\text{TSA}_1 = 4\pi r^2$
The total surface area of a hemisphere with radius R,
$⇒\text{TSA}_2 = 3\pi R^2$
Given that the radius of the hemisphere is twice that of the sphere, ($R = 2r$).
$⇒\text{TSA}_2 = 3\pi (2r)^2 = 12\pi r^2$
The ratio of the total surface area of the hemisphere to the sphere.
$⇒\frac{\text{TSA}_2}{\text{TSA}_1} = \frac{12\pi r^2}{4\pi r^2} = 3$
Hence, the correct answer is 3 : 1.

Know More About

Related Questions

TOEFL ® Registrations 2024
Apply
Accepted by more than 11,000 universities in over 150 countries worldwide
Manipal Online M.Com Admissions
Apply
Apply for Online M.Com from Manipal University
View All Application Forms

Download the Careers360 App on your Android phone

Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile

150M+ Students
30,000+ Colleges
500+ Exams
1500+ E-books