The UPSC mains GS-3 paper syllabus has various subjects like Economics, Science and Technology. Science and technology in UPSC is mostly concerned with current Affairs. but it is necessary to understand the basics of science.


  • What is Oscillation?
  • Oscillation Motion
  • Simple Harmonic Motion


  • Oscillation is defined as the process of repeating variations of any quantity or measure about its equilibrium value in time. Oscillation can also be defined as a periodic variation of a matter between two values or about its central value.
  • The term vibration is used to describe the mechanical oscillations of an object. However, oscillations also occur in dynamic systems or more accurately in every field of science. Even the beating of our heart creates oscillations​. Meanwhile, objects that show motion around an equilibrium point are known as oscillators.
  • A sine wave is a perfect example of oscillation. Here the wave moves between two points about a central value. The height or the maximum distance that the oscillation takes place is called the amplitude and the time taken to complete one complete cycle is called the time period of the oscillation. Frequency is the number of complete cycles that occur in a second. Frequency is the reciprocal of the time period.

F = 1 / T

Where F is the frequency of oscillation

And T is the time period of the oscillation.

Oscillation Motion

In simple terms, we can say that when an object is swinging from side to side in a mechanical system this movement can be termed as oscillation motion. In this type of motion, the potential energy usually changes to kinetic energy. An oscillation motion consists of one complete cycle.

Variables of Oscillation

  • Amplitude is the maximum displacement from the equilibrium point. If a pendulum swings one centimeter from the equilibrium point before beginning its return journey, the amplitude of oscillation is one centimeter.
  • Period is the time it takes for a complete round trip by the object, returning to its initial position. If a pendulum starts on the right and takes one second to travel all the way to the left and another second to return to the right, its period is two seconds. ​Period is usually measured in seconds.
  • Frequency is the number of cycles per unit of time. Frequency equals one divided by the period. Frequency is measured in Hertz, or cycles per second.

Simple Harmonic Motion

The motion of a simple harmonic oscillating system—when the restoring force is directly proportional to that of the displacement and acts in the direction opposite to that of displacement—can be described using sine and cosine functions. An example is a weight attached to a spring. When the weight is at rest, it's in equilibrium. If the weight is drawn down, there's a net restoring force on the mass (potential energy). When it's released, it gains momentum (kinetic energy) and keeps moving beyond the equilibrium point, gaining potential energy (restoring force) that will drive it in oscillating down again.