# 16 Lecture

## Oscillations – II

Oscillations are a common phenomenon that can be observed in many physical systems, ranging from a simple pendulum to complex electronic circuits.

## Important Mcq's Midterm & Finalterm Prepration Past papers included

What happens to the amplitude of damped oscillations over time?

a) It increases

b) It remains constant

c) It decreases

d) It oscillates

What is resonance in forced oscillations?

a) The amplitude of oscillation decreases

b) The frequency of the external force is lower than the natural frequency of the oscillator

c) The frequency of the external force is equal to the natural frequency of the oscillator

d) The frequency of the external force is higher than the natural frequency of the oscillator

Answer: c) The frequency of the external force is equal to the natural frequency of the oscillator

What is the equation that describes damped oscillations?

a) The harmonic oscillator equation

b) The damped harmonic oscillator equation

c) The forced harmonic oscillator equation

d) The coupled harmonic oscillator equation

Answer: b) The damped harmonic oscillator equation

What are forced oscillations?

a) Oscillations that occur naturally in a system

b) Oscillations that are affected by external forces

c) Oscillations that are damped over time

d) Oscillations that are coupled to other oscillators

Answer: b) Oscillations that are affected by external forces

What is the equation that describes coupled oscillations?

a) The harmonic oscillator equation

b) The damped harmonic oscillator equation

c) The forced harmonic oscillator equation

d) The coupled harmonic oscillator equation

Answer: d) The coupled harmonic oscillator equation

What is synchronized behavior in coupled oscillations?

a) The oscillators all oscillate with the same frequency and phase

b) The oscillators oscillate with different frequencies and phases

c) The oscillators all come to rest

d) The oscillators oscillate with increasing amplitudes over time

Answer: a) The oscillators all oscillate with the same frequency and phase

What happens to the period of a damped oscillator over time?

a) It increases

b) It remains constant

c) It decreases

d) It oscillates

What is beating in coupled oscillations?

a) The amplitude of oscillation decreases

b) The amplitude of oscillation increases

c) The frequency of the oscillation decreases

d) The amplitude of oscillation varies periodically

Answer: d) The amplitude of oscillation varies periodically

What causes damping in oscillations?

a) An external periodic force

b) Friction or air resistance

c) Resonance

d) Coupling to other oscillators

Answer: b) Friction or air resistance

What is the behavior of a forced oscillator when the frequency of the external force is much higher than the natural frequency of the oscillator?

a) The amplitude of the oscillation is very large

b) The amplitude of the oscillation is very small

c) The oscillator does not oscillate

d) The behavior of the oscillator depends on the amplitude of the external force

Answer: b) The amplitude of the oscillation is very small

## Subjective Short Notes Midterm & Finalterm Prepration Past papers included

What is damping in oscillations?

Answer: Damping is the process of reducing the amplitude of oscillations over time due to some external factors, such as friction or air resistance.

What is the equation that describes damped oscillations?

Answer: The equation that describes damped oscillations is the damped harmonic oscillator equation, which takes into account the damping force proportional to the velocity of the oscillator.

What happens to the amplitude of damped oscillations over time?

Answer: The amplitude of damped oscillations decreases exponentially over time.

What are forced oscillations?

Answer: Forced oscillations occur when a periodic external force is applied to a system, and the behavior of the oscillator is affected by the frequency and amplitude of the external force.

What is resonance in forced oscillations?

Answer: Resonance occurs in forced oscillations when the frequency of the external force is equal to the natural frequency of the oscillator, resulting in a large amplitude of oscillation.

What are coupled oscillations?

Answer: Coupled oscillations occur when two or more oscillators are connected in some way, such that the motion of one oscillator affects the motion of the other(s).

What is beating in coupled oscillations?

Answer: Beating occurs in coupled oscillations when two oscillators of slightly different frequencies are connected, and the amplitude of the oscillation varies periodically.

What is the equation that describes coupled oscillations?

Answer: The behavior of a system of coupled oscillators can be described using a set of coupled differential equations, one for each oscillator.

What is synchronized behavior in coupled oscillations?

Answer: Synchronized behavior occurs in coupled oscillations when the oscillators all oscillate with the same frequency and phase.

Why is the study of oscillations important in science and engineering?

Answer: The study of oscillations is important in science and engineering because it helps us understand the behavior of natural systems and design stable and reliable systems that exhibit oscillatory behavior.

Oscillations are a common phenomenon that can be observed in many physical systems, ranging from a simple pendulum to complex electronic circuits. In my previous article on oscillations, I discussed the basic concepts of oscillations and some of the important characteristics of simple harmonic motion. In this article, I will delve deeper into the study of oscillations and explore some of the more complex aspects of this fascinating physical phenomenon.

### Damped Oscillations:

In real-world systems, oscillations are often subject to some form of damping, which is the process of reducing the amplitude of the oscillation over time. This can occur due to a variety of factors, such as air resistance or friction. Damped oscillations are characterized by the fact that the amplitude of the oscillation decreases over time, and the system eventually comes to rest. The behavior of a damped oscillator can be described using a differential equation known as the damped harmonic oscillator equation. This equation takes into account the damping force, which is proportional to the velocity of the oscillator. The solution to this equation is a damped sinusoidal function, where the amplitude of the oscillation decreases exponentially over time. The frequency of the oscillation remains constant, but the period of the oscillation increases as the amplitude decreases.

### Forced Oscillations:

Forced oscillations occur when a periodic external force is applied to a system. The behavior of a forced oscillator can be quite complex, depending on the frequency and amplitude of the external force. When the frequency of the external force is equal to the natural frequency of the oscillator, the amplitude of the oscillation can become very large, a phenomenon known as resonance. In some cases, resonance can cause the system to become unstable, leading to catastrophic failure. The behavior of a forced oscillator can be described using the equation of motion for a damped harmonic oscillator, with an additional term for the external force. The solution to this equation is a superposition of the natural oscillation of the system and the external force. The amplitude of the oscillation depends on the frequency of the external force, with resonance occurring when the frequency of the external force is equal to the natural frequency of the oscillator.

### Coupled Oscillations:

Coupled oscillations occur when two or more oscillators are connected in some way, such that the motion of one oscillator affects the motion of the other(s). This can occur in a variety of physical systems, such as coupled pendulums or electrical circuits. Coupled oscillations can exhibit a variety of interesting behaviors, such as beating, where the amplitude of the oscillation varies periodically. The behavior of a system of coupled oscillators can be described using a set of coupled differential equations, one for each oscillator. The solution to these equations depends on the initial conditions of the system and the coupling between the oscillators. In some cases, the system can exhibit synchronized behavior, where the oscillators all oscillate with the same frequency and phase.

### Conclusion:

Oscillations are a fascinating physical phenomenon that occur in a wide variety of systems. The study of oscillations is important in many fields of science and engineering, from the design of electrical circuits to the development of earthquake-resistant buildings. Understanding the behavior of oscillating systems is crucial in order to predict their behavior and design systems that are stable and reliable. In this article, we have explored some of the more complex aspects of oscillations, such as damped oscillations, forced oscillations, and coupled oscillations. These phenomena exhibit a wide range of behaviors, from simple sinusoidal motion to complex patterns of motion. By understanding these behaviors, we can develop a deeper understanding of the natural world and create new technologies that improve our lives.