Surface Area of a Sphere

Q. If the surface area of a sphere is $144\pi m^2$, then its volume (in $m^3$) is

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. ₹ 2034.72

2. ₹ 1076.32

3. ₹ 1017.36

4. ₹ 508.68

Q.

Total surface area of a sphere is directly proportional to __ of radius of the sphere.

Q.

Find (i) the curved surface area and (ii) the total surface area of a hemisphere of radius 7 cm. [2 MARKS]

Q. Area of region enclosed by ellipse $x^2+4y^2=1$ is ______

1. $\frac{\pi }{2}$
2. $\pi$
3. $2\pi$
4. $4\pi$

Q.

If we take a circle and a sphere of the same radius, then the surface area of the sphere is ___ times the area of the circle.

Q.

The surface areas of two spheres are in the ratio 1 : 4. Find the ratio of their volumes.
(2 marks)

Q.

If we take a circle and a sphere of the same radius, then the surface area of the sphere is ___ times the area of the circle.

Q.

If we take a circle and a sphere of the same radius, then the surface area of the sphere is ___ times the area of the circle.

Q. For a sphere and hemisphere of radius 'r', match the following.

1. 4πr${}^2$
2. 3πr${}^2$
3. 2πr${}^2$

Q. The surface area of a sphere (in sq. cm) of radius 7 cm is:

1. 343
2. 480
3. 528
4. 616

Q. For a sphere and hemisphere of radius 'r', match the following.

1. 2πr${}^2$
2. 4πr${}^2$
3. 3πr${}^2$

Q. Question 5
The volumes of the two spheres are in the ratio 64:27. Find the ratio of their surface areas.