Question

The working principle of a washing machine is?
A. Reverse osmosis
B. Dialysis
C. Centrifugation
D. Diffusion

Answer 1

Hint: Try to imagine how a washing machine might work. Then compare it to the physical processes. You will get the answer.

Complete step by step solution:
When we put cloth and soap in the washing machine to mix it together and then the machine rotates or spins at a very high speed which forces the dirt and soap in the clothes to leave the surface of the clothes. It will clean the surface of the cloth and then we can again spin the machine to partially dry the clothes in it. The process uses the centrifugal force to both clean and dry the clothes in the machine.
Centrifugation is the process with which we can separate particles depending on their size, shape and density from a solution. In this process we put the solution where the particles are suspended, in a centrifuge tube. Then we spin the tube at a defined speed for a time interval. After that we will get the suspended particles at the bottom of the tube and then we can separate the liquid from the particles. It uses the centrifugal force to move the particles to the bottom of the tube.
In the above processes, both processes use the centrifugal force and act in the same manner. So, we can say that the working principle of the washing machine is centrifugation.

Correct answer is option (C)

Note: A body moving on a circular path has two forces acting on it. One is centripetal force and the other is centrifugal force.
A body moving in a circular path will constantly change direction and hence will change velocity. It means that it has an acceleration. So, from Newton’s 2nd law we can say that a force is acting constantly in the body towards the centre. It is called centripetal force.
A body moving in a circular path will experience an outward force which depends on its mass, velocity and the radius of the circular path. It is called centrifugal force. The centrifugal force is a fictitious force.
Both the centrifugal and centripetal forces are equal but opposite in direction.