Cylinder and Its Surface Area

Q.

I fold a rectangular piece of plane paper into a circular fold. The radius of the circle along which fold is done is 2K cm. The length of unfolded dimension is M cm. I get a solid figure. What is the figure and what is its surface area (in $c{m}^2$)?

1. Cylinder, 4πK

2. Cylinder, 4πMK

3. Sphere, πMK

4. Cone, 4πMK

Q.

Question 59

State whether the following statement is true or false:

Two cylinders with equal volume will always have equal surface area.

Q.

Four pieces of wooden sticks $ A, B, C$ and $ D$ are placed along the length of $ 30 cm$ long scale as shown in the figure. Which one of them is $ 3.4 cm$ in length?

Q.

Find the height of a cylinder if its total surface area is 2552 $c{m}^2$ and the radius is 14 cm.

1. 13 cm
2. 16 cm
3. 15 cm
4. 14 cm

Q.

A pencil box of length 20cm consists of a pencil of length 18cm along with a sharpener of length 3cm placed on top of the pencil. Is this possible?

1. True

2. False

Q. Find the cost of painting 15 cylindrical pillars of a building at Rs 2.50 per square metre if the diameter and height of each pillar are 48 cm and 7 metres respectively.

Q. The height of a cylinder is $15cm$. Its curved surface area is $660c{m}^2$. Find its radius.

Q. A farmer built a granary in the shape of a cylinder to store his crop . The capacity of the granary is 768 pi r ft of power 3 and the radius of its circular base is 8 ft .The farmer want to builds another granary of the same volume but with half the radius of the circular base , then the height of the new granary will be ?

Q. If square sheet of area 3.14 $c{m}^2$ is shaped into circular sheet, then find the estimated circumference of that sheet for nearset hundredth (use pi=3.14)

1. 6.28 cm
2. 3.28 cm
3. 7.84 cm
4. 4.28 cm