Curved Surface Area & Total Surface Area of Cone

Q.

A piece of cloth is required to completely cover a solid object. The solid object is composed of a hemisphere and a cone surmounted on it. If the common radius is 7 m and height of the cone is 1 m, what is the area of cloth required? $(\sqrt{2}=1.414)$

1. 563 $m^2$
2. 262.39 $m^2$
3. 463.1 $m^2$
4. 662.39 $m^2$

Q.

A tent is in the form of a cylinder of diameter $4.2m$ and height $4m$, surmounted by a cone of equal base and height $2.8m$. find the cost of canvas for making the tent at ₹ $100$ per sq.m.

1. Rs $6590$

2. Rs $7590$

3. Rs $8590$

4. Rs $9876$

Q.

A piece of cloth is required to completely cover a solid object. The solid object is composed of a hemisphere and a cone surmounted on it. If the common radius is 7m and height of the cone is 1m, what is the area of cloth required? ($\sqrt{2}=1.414$)

1. 262.39 m²

2. 463.39 m²

3. 662.39 m²

4. 563 m²

Q.

If a sector of radius 8cm with central 120⁰ is folded into a cone, the slant height of cone is:

1. 4 cm

2. 6 cm

3. 8 cm

4. 2.5 cm

Q.

A sector whose central angle is 120 degrees with radius 12 cm is rolled into a cone. The radius of the cone is

1. 200

2. 80

3. 150

4. 100

Q.

If a sector of radius 9 cm with central 240⁰ is folded into a cone, the slant height of cone is

1. 6 cm

2. 2 cm

3. 3 cm

4. 9 cm

Q. The diameter of the base of a right circular cone is 21cm and its height is 20cm.Find the curved surface area of the cone.

1. $3300c{m}^2$
2. $1914c{m}^2$
3. $26720c{m}^2$
4. $1386c{m}^2$

Q. What is the pair of figures we would get if we cut open a right circular cone of radius $r$ and slant height $l$?

1. 
2. 
3. 
4. None of the above

Q.

A cylinder is surmounted by a cone as shown in the figure. Find the total surface area solid formed. (in $c{m}^2$). (Take $\pi =3.14$)

1. 900

2. 855.05

3. 820.75

4. 830.75

Q.

A hemisphere of radius 21cm, made up of iron is melted and moulded to form a cone of height 21 cm. What is the ratio of the curved surface area of the cone to that of the hemisphere?

1. $1:2$

2. $2\sqrt{2}:3$

3. $2\sqrt{3}:\sqrt{5}$

4. $\sqrt{3}:\sqrt{2}$