The radius of a hemispherical balloon increases from 6 cm to 12 cm as air is being pumped into it. The ratios of the surface areas of the balloon in the two cases is

1 : 4

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

1 : 3

No worries! We‘ve got your back. Try BYJU‘S free classes today!

2 : 3

No worries! We‘ve got your back. Try BYJU‘S free classes today!

2 : 1

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is A 1 : 4
Total surface area of a Hemisphere $= 2 π r^{2} + π r^{2} = 3 π r^{2}$
$r = 6, S u r f a c e a r e a = 3 π (6)^{2} = 36$
$r = 12, S u r f a c e a r e a = 3 π (12)^{2} = 144$
Ratio = $36 : 144$
= $1 : 4$

Suggest Corrections

Similar questions

Q. Question 10
The radius of a hemispherical balloon increases from 6 cm to 12 cm as air is being pumped into it. The ratio of the surface areas of the balloon in the two cases is:

A) 1:4
B) 1:3
C) 2:3
D) 2:1

Q. The radius of a hemispherical balloon increases from 7 cm to 14 cm as air is being pumped into it. Find the ratios of the surface areas of the balloon in the two cases.

Q. The radius of a hemispherical balloon increases from 6 cm to 12 cm as air is being pumped into it. The ratio of the surface areas of the balloons in two cases is
(a) 1 : 4
(b) 1 : 3
(c) 2 : 3
(d) 1 : 2

Q. The radius of a spherical balloon increases from 7

c m

14

c m

as air is being pumped into it. Find the ratio of surface areas of the balloon in two cases.

Question 4
The radius of a spherical balloon increases from 7 cm to14 cm as air is being pumped into it. Find the ratio of surface areas of the balloon in the two cases.

Join BYJU'S Learning Program

The radius of a hemispherical balloon increases from 6 cm to 12 cm as air is being pumped into it. The ratios of the surface areas of the balloon in the two cases is

The correct option is A 1 : 4Total surface area of a Hemisphere =2πr2+πr2=3πr2r=6,Surface area=3π(6)2=36r=12,Surface area=3π(12)2=144Ratio = 36:144=1:4

The correct option is A 1 : 4
Total surface area of a Hemisphere $= 2 π r^{2} + π r^{2} = 3 π r^{2}$
$r = 6, S u r f a c e a r e a = 3 π (6)^{2} = 36$
$r = 12, S u r f a c e a r e a = 3 π (12)^{2} = 144$
Ratio = $36 : 144$
= $1 : 4$