Surface Area of a Sphere

Q. The total surface area of a sphere of radius 7 cm = cm ${}^2$.

1. 616
2. 308
3. 668
4. 334

Q.

Find the surface area of a sphere of diameter $21cm$.

Q. The surface area of a sphere is 32π cm${}^2$. Find the radius and volume of this sphere?

1. $8cm,\frac{64\pi }{3}c{m}^3$
2. $16cm,\frac{64\pi }{3}c{m}^3$
3. $2\sqrt{2}cm,\frac{64\sqrt{2}\pi }{3}c{m}^3$
4. $2\sqrt{2}cm,\frac{64\pi }{3}c{m}^3$

Q.

Find the total surface area of hemisphere of radius 7 cm.(Take $\pi$ = $\frac{22}{7}$).

Q.

The diameter of a roller is $84cm$ and its length is $120cm$. It takes $500$ complete revolutions to move once over to level a playground. Find the area of the playground in metre square.

Q.

The diameter of a cylindrical well is $\mathbf{4}\mathbf{.}\mathbf{5}\mathbf{}\mathit{m}$ and depth of the well is $\mathbf{14}\mathbf{}\mathit{m}$. Find the cost of cementing its inner curved surface at the rate of $\mathbf{12}\mathbf{.}\mathbf{50}$ rupees per square metre.

Q.

If the diameter of a sphere is decreased by $25\%$, then its curved surface area decreases by:

1. $43.50\%$

2. $44.25\%$

3. $43.75\%$

4. $75.43\%$

Q.

A cricket ball of radius $r$ is exactly fitted in a cylindrical tin as shown in the figure below. The ratio of surface areas of cricket ball to the surface area of tin is

1. 2:3

2. 3:1

3. 3:2

4. 1:3

Q.

Find the surface area of a sphere of radius $10.5cm$.

Q.

A hollow sphere in which a circus motorcyclist performs his stunts has an inner diameter of $7m$. Find the area available to the motorcyclist for riding.

Q. You are holding a spherical ball of radius 3.5 cm in your fist. You observe that 30% of area is uncovered. Then find the area of the ball uncovered. (Take $\pi =\frac{22}{7}$)

1. $26.2{\text{cm}}^2$
2. $46.2{\text{cm}}^2$
3. $36.2{\text{cm}}^2$
4. $16.2{\text{cm}}^2$

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

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

Q.

In a circus, a motorcyclist performs his stunts in a hollow sphere. The thickness of the sphere is negligible. If the diameter of the hollow sphere is $14m,$ then find the area available for the motorcyclist to perform stunts. $(\text{Take}\pi =\frac{22}{7})$

1. 516m²

2. 616m²

3. 586m²

4. 486m²

Q.

A cricket ball of radius r is exactly fitted in a cylindrical tin as shown in the figure below. The ratio of surface area of the cricket ball to the surface area of the tin is

1. 1:3

2. 2:3

3. 3:1

4. 3:2

Q. If a sphere has the same curved surface area as total surface area of cone of vertical height $40cm$ and radius $30cm$ then the radius of the sphere is:

1. $10\sqrt{6}$ cm
2. $10\sqrt{3}$ cm
3. $10\sqrt{2}$ cm
4. $12cm$

Q.

In a circus, a motorcyclist performs his stunts in a hollow sphere. Assume the thickness of the sphere to be negligible. If the diameter of the hollow sphere is 14 m, then find the area available for the motorcyclist to perform his stunts.(Take $\pi =\frac{22}{7}$)

1. 516$m^2$

2. 616$m^2$

3. 586$m^2$

4. 486$m^2$

Q. If a circle and a sphere have the same radius, then CSA of sphere is times the area of the circle.

1. 4
2. 3
3. 2

Q. The volume of a hemisphere is $2425\frac{1}{2}$. Find its curved surface area.

Q.

The diameter of a roller is $84cm$ and its length is $120cm$. It takes $500$ complete revolutions to move once over to level a playground. Find the area of the playground in $m^2$.

1. $1584m^2$

2. $1554m^2$

3. $1284m^2$

4. none of these

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. A cricket ball of radius r is exactly fitted in a cylindrical tin as shown in the figure below. The ratio of surface areas of cricket ball to the surface area tin is

1. 3:2

2. 1:3

3. 2:3

4. 3:1

Q.

A cricket ball of radius r is exactly fitted in a cylindrical tin as shown in the figure below. The ratio of surface areas of the cricket ball to the surface area of tin is ___.

1. 1:3

2. 2:3

3. 3:1

4. 3:2

Q.

A cricket ball of radius R is exactly fitted in a cylindrical tin. The ratio of surface areas of cricket ball to the tin is

Q.

If a hemisphere has radius __ cm, then total surface area of the hemisphere is 9.42 ${cm}^2$.

(Take $\pi$ = 3.14)

Q.

Find the total surface area of hemisphere of radius 7 cm.(Take $\pi$ = $\frac{22}{7}$ )

Q.

A cricket ball of radius R is exactly fitted in a cylindrical tin. Find the ratio of surface areas of the cricket ball to the tin.

Q.

If a hemisphere has radius __ cm, then total surface area of the hemisphere is 9.42 ${cm}^2$.

(Take $\pi$ = 3.14).

Q. If CSA of a sphere is 154 $c{m}^2$, then its radius is ___ cm.

1. 3.5

Q.

In a circus, a motorcyclist performs his stunts in a hollow sphere.Neglect the thickness of sphere. If the diameter of the hollow sphere is 14 m, then find the area available for the motorcyclist to perform stunts.(Take $\pi =\frac{22}{7}$)

1. 516m²

2. 616m²

3. 586m²

4. 486m²

Q. The volume of a hemisphere is $2425\frac{1}{2}c{m}^3$. Find its curved surface area. $[Use\pi =\frac{22}{7}].$