A cylinder is a three-dimensional solid that consists of two parallel circular bases connected to each other with the help of a curved surface. Cylinder, the word has been derived from the Latin word ‘cylindrus’ and the Greek word ‘kylindros’. The line passing from the centre or joining the centres of two circular bases of a cylinder is called the axis. The distance between the circular bases of the cylinder is the perpendicular distance and is represented as height or by the letter ‘h’. The distance between the centre of the base of a cylinder and the outer boundary of the cylinder is the radius of the cylinder as is represented by ‘r’.
Types of a Cylinder
In geometry, there are four different types of cylinders, namely:
1. Right Circular Cylinder
If the axis of the cylinder is perpendicular to the centre of the base, it is called the right circular cylinder.
2. Oblique Cylinder
If the curved part of the cylinder leans over the base, then such a cylinder is known as an oblique cylinder. In an oblique cylinder, the axis of the cylinder is not perpendicular to the circular bases. The Leaning Tower of Pisa is a prominent example of an oblique cylinder.
3. Elliptic Cylinder
As the name itself suggests, a cylinder whose base is in the form of an ellipse is known as an elliptic cylinder.
4. A right Circular Hollow Cylinder or Cylindrical Shell
The right circular hollow cylinder or a cylindrical shell consists of two right circular cylinders that are fixed one inside the other. The point of the axis of both the cylinders is common and is perpendicular to the central base. It is different from the right circular cylinder because it is hollow in nature.
Mathematical Formulae related to a Cylinder
1. The lateral Surface area of the cylinder = 2πrh square units.
2. The total surface area of the cylinder, A = 2πr(r+h) square units.
3. The volume of the Cylinder, V = πr²h cubic units.
here, ‘r’ is the radius of the cylinder and ‘h’ denotes the height of the cylinder.
Properties of a Cylinder
Some of the important properties of the cylinder are as follows:
1. The bases of the cylinder are always congruent and parallel to each other.
2. If the locus of a line moving parallel and fixed distance from the axis, a right circular cylinder is produced.
3. A cylinder is quite similar to a prism; the only difference is that it has the same cross-section everywhere.
Examples of a Cylinder
1. Pencil Holder
A pencil holder kept on the top of your study table or office desk is a prominent example of cylindrical objects present around us. A pencil holder typically comprises a solid circular base, a curved surface attached to the circumference of the base, and a hollow circular top.
2. Canned Food
Canned foods or cold drink cans are cylindrical in shape. Hence, cylinder-shaped objects can be observed very easily in our daily life.
3. Gas Cylinder
Gas cylinders are a perfect example of cylindrical objects present around us. The curved surface joining the two parallel circular bases can be observed easily.
A cell or an electrochemical cell functions as a dc power source and is used to supply electrical power to the gadgets. Generally, these cells are manufactured in the shape of cylinders. Hence, the cells that power your TV remote, trimmer, AC remote, and other daily use objects, are a classic example of cylindrical objects used in everyday life.
5. Oil Tank
The large metallic storage tanks used to store oil are generally cylindrical in shape. Hence, oil tanks are yet another example of cylinder-shaped objects used in real life.
An unsharpened pencil is yet another example of a cylinder because it consists of two circular and parallel bases, namely the top and the base of the pencil, and the curved wooden part.
Dust bins are mostly cylindrical in shape that consist of a hollow top and a rigid base.
A bucket is a common object used in everyday life that is shaped like a cylinder.
9. Coffee Cup
Coffee cups, drinking glasses, tumblers etc. are mostly cylindrical in shape. Hence, the examples of cylindrical objects in real life can be easily observed by looking inside the utensil cabinet of your kitchen.
10. Log of a Wood
A log of wood is generally cut in a cylindrical shape. Also, one can easily visualise the cylinder shape by looking at the trunk of the tree.
11. Toilet Paper Roll
Toilet paper rolls are cylindrical in shape.
12. Perfume or Deodorant Bottle
Perfume or deodorant bottles are generally cylindrical in shape; however, there are certain other designer shapes in which the colognes are packed by the manufacturer.
13. Water Tank or Water Bottle
A water tank that is usually installed on the rooftop of a building or an apartment is generally cylindrical in shape. In a similar manner, water bottles are a prominent example of cylinder-shaped objects used in everyday life.
Candles come in a variety of shapes, sizes, and colours. One of the most popular geometric shapes opted by candle makers is the cylinder. Some of the jar candles are also cylindrical in shape.
The chimneys installed near industries or factories are comparatively longer than the domestic chimneys. This is because the height enables the toxic gases to be released into the upper atmosphere. You can easily observe that the industrial chimneys are mostly cylindrical in shape.
Snare drum, kettledrum, tabla, slit drum, bass drum, etc. are some of the drums that are shaped like a cylinder.
A beaker used in the chemistry lab to store chemicals and perform experiments is generally cylindrical in shape.
18. Test Tube
Test tubes consist of a hollow circular top and a curved base connected together with the help of a curved surface area. Hence, it is yet another example of cylindrical shaped objects used in daily life.
A cake seems circular while looking at it from the top but, it is definitely an example of the cylindrical shape. This is because there exists a curved surface area that connects the base and the top layer of the cake.
wells also consist of curved walls, a rigid base and a hollow top. Hence, a well is a prominent example of cylindrical objects present around us.