C.S.A of Hemisphere

Q. A hemispherical bowl is made of brass, 7 cm thickness. The inner radius of the bowl is 7 cm. Find the ratio of outer surface area to inner surface area.

1. $4:1$
   
2. $1:4$
   
3. $1:2$
4. $2:1$

Q. A hemispherical bowl is made up of stones whose thickness is 7 cm. If the inner radius is 35 cm, find the total surface area of the bowl.

1. $20463.38c{m}^2$
2. $18942c{m}^2$
3. $18992c{m}^2$
4. $15942c{m}^2$

Q. Question 3
In a huge park people are concentrated at three points (see the given figure)

A: where there are different slides and swings for children,
B: near which a man-made lake is situated,
C: which is nearto a large parking and exit.
Where should an ice-cream parlour be set up so that maximum number of persons can approach it?

Q. What is the percentage change in the curved surface area of a hemisphere if the new radius is twice the initial radius?

1. 150%

2. 300%

3. 100%

4. 50%

Q. What's the percentage change in the curved surface area of a hemisphere if the radius is doubled the initial radius?

1. 300 %
   
2. 50 %
   
3. 100 %
   
4. 150 %
   

Q. What's the percentage change in the curved surface area of a hemisphere if the radius is doubled the initial radius?

1. 150 %
   
2. 100 %
   
3. 50 %
   
4. 300 %
   

Q.

The cost of painting outer curved surface of a hollow hemispherical iron bowl at the rate of ₹ 2 per cm square is ₹ 1256. If the thickness of the iron is 1 cm, find the cost of painting the inner curved surface of the bowl. (Take $\pi$ = 3.14)

1. ₹ 1017.36

2. ₹ 508.68

3. ₹ 1076.32

4. ₹ 2034.72

Q. CSA of a hemisphere of radius 'r' is 2πr${}^2$.

1. True
2. False

Q. What's the percentage change in the curved surface area of a hemisphere if the radius is doubled the initial radius?

1. 100 %
   
2. 300 %
   
3. 150 %
   
4. 50 %
   

Q. What's the percentage change in the curved surface area of a hemisphere if the radius is doubled the initial radius?

1. 100 %
   
2. 300 %
   
3. 50 %
   
4. 150 %
   

Q. A hemispherical bowl is made up of stones whose thickness is 7 cm. If the inner radius is 35 cm, find the total surface area of the bowl.

1. $20463.38c{m}^2$
2. $18942c{m}^2$
3. $15942c{m}^2$
4. $18992c{m}^2$

Q. What's the percentage change in the curved surface area of a hemisphere if the radius is doubled the initial radius?

1. 100 %
   
2. 50 %
   
3. 300 %
   
4. 150 %
   

Q. What's the relation between the curved surface area of a hemisphere and the total surface area of hemisphere?

1. $CSA=\frac{2}{3}\times TSA$
2. $CSA=\frac{3}{2}\times TSA$
3. $TSA=\frac{2}{3}\times CSA$
4. $CSA=\frac{4}{3}\times TSA$

Q. A hemispherical bowl is made of brass, 7 cm thickness. The inner radius of the bowl is 7 cm. Find the ratio of outer surface area to inner surface area.

1. $4:1$
   
2. $1:4$
   
3. $2:1$
4. $1:2$

Q. If the curved surface area of a hemisphere is $8\pi m^2$, then the radius is.

1. $2m$
2. $4m$
3. $8m$
4. $6m$