![MCQs [2024]](https://engineeringinterviewquestions.com/wp-content/uploads/2021/02/Interview-Questions-2.png)
Let us draw a circle and a sphere on a piece of paper. What do we find? Both the shapes are the same because of their round format. Thus, many of us get confused in understanding them. Then what is the difference between a circle and a sphere? The basic sphere and circle difference is that the circle is 2-Dimensional, and a sphere is 3-Dimensional. Deriving from the basic difference, we can get another difference that is one can compute the area of a circle, but for a sphere, we have to find its volume.
Circle
A circle is considered a type of line. A circular line consists of a set of points with a property that all the points present in that line are from a uniform distance from a fixed point on a plane. It consists of a closed-loop that divides plains into inner and outer sections. The various properties of a circle are center, circumference, tangent, and chord. Radius is connected to its center through the lines, and “r” depicts the length of the radius of that particular circular line. Ellipse is a special case of a circle with a set of points with a constant sum of the distance between the two fixed points in a plane. These two fixed points are known as focus and center, which are the same in the case of a circle. In the inner circle, one can find three sets of points that are not present in the same direction, which defines a triangle’s edges. Some examples of the circle are disc, clock, etc.
()
Sphere
Unlike a circle, a sphere is a three-dimensional figure. All the points of a sphere are equidistant from the center at any of the axes. You can calculate the volume, surface area, and radius of the sphere easily.
The line connecting the distant edge points is known as the diameter of the sphere. There is no circumference present in the sphere. There are small circles and hemispheres present in the sphere. Some popular examples of spheres include marble, football, and water droplets.
()
Types of Spheres
-
Solid Sphere – Solid object, which is in the form of a sphere, is known as a solid sphere. A solid sphere is filled with the same material from which it is made up of.
-
Hollow Sphere– When a solid sphere is cut from the middle and a big solid that is taken out of it, leaving a spherical shell behind, is called a hollow sphere.
()
Difference between Circle and Sphere
Because of the round shape of both circle and sphere, people find both similar to each other. But in reality, both are quite different from each other. Let us illustrate some major differences between circle and sphere.
|
S. No |
Property |
Circle |
Sphere |
|
1 |
Definition |
Circle refers to the closed curved line and all the points of a circle are present at the same distance from its center in a Plane. |
A sphere is a round object in space and All the points in a sphere are equidistant at any axes from the center in a 3D space. |
|
2 |
Dimension |
A circle is a 2D figure. |
A sphere is a 3D object. |
|
3 |
Determination |
In the case of a circle, Area is determined. |
In the case of a Sphere, Surface area and Volume are determined. |
|
4 |
Area/ Surface area |
The area of a circle is πr2 |
The Surface area of a sphere 4πr2 |
|
5 |
Volume |
A Circle is a 2D shape and do not have volume |
The Volume of a Sphere is [frac{4}{3} pi r^{2}] |
|
6 |
Diameter |
The diameter of a circle is double the radius = 2r |
The diameter of a sphere is 2r. |
|
7 |
Circumference |
The circumference of a circle is 2πr. |
Sphere doesn’t have a circumference. |
|
8 |
Standard Equation |
The standard equation of a circle is (x-a)2+(y-b)2=r2, where (a,b) is the center of the circle and r is the radius of the circle. |
The standard equation of a sphere is (x-a)2+(y-b)2+(z-c)2=r2, where (a,b,c) is the center of the sphere and r is the radius of the circle. |
|
9 |
Consideration |
A circle is considered as a figure. |
A sphere is considered an object. |
|
10 |
Examples |
Coins, CD, Wheels. |
Planets, Oranges, a Globe |
Solved Example
-
How would you calculate the surface area of a ball whose radius is 5 cm?
Ans: Firstly, we would like to disclose that the ball is a sphere. The radius of the ball is given as 5 cm.
Surface area of sphere = 4 πr2
Therefore, the surface area of the ball = 4π(5)2
= 4 x π x 25
= 100 π sq.cm.