Sound

# Class 10 Physics Chapter 7 Sound Important Questions

Sound is a type of mechanical wave that results from the back and forth vibration of particles in the medium through which it's travelling. It can propagate through gases, liquids, solids, and plasmas, but not in a vacuum, as there are no particles to vibrate. In class 10 Sound important questions and answers, there are a lot of questions which are based on longitudinal and transverse waves,sonar,frequency,amplitude,wavelength,echo and pitches that will make your understanding better for this chapter.

## Introduction

Sound waves are mechanical waves, meaning they need a medium – be it solid, liquid, or gas – to propagate. They are also longitudinal in nature, which means that the particles of the medium move parallel to the direction of the wave. When an object, like a tuning fork or a drum membrane, is set into motion, it creates compressions and rarefactions in the surrounding medium due to its vibrational motion. These alternate regions of high and low pressure propagate away from the source as sound waves. If you want to prepare well then below are some sound class 10 ICSE questions.

## What are Sound?

The sound is defined as vibration that propagates as an audible wave of pressure, through a medium such as a gas, liquid or solid. the most common SI unit of sound that is used is Decibel which is abbreviated as dB.In simple terms, the reflection of sound is actually similar to the reflection of light. Sound abides different laws of reflection, in which the angle of incidence does prove equal to the angle of reflection. In addition, sound rebounds from the surface of either solid or liquid similar to a billiard ball. For successfully experiencing the reflection of sound, it is important that the surface should be polished or rough, and that too of a considerably large size. If you want to practice more questions and clear your understanding, then oswal.io provides you with class 10 Sound important questions and answers.

### Class 10 Sound Important Questions and Answers

#### (a) The amplitude does not change with time(b) There is no loss of energy in the process(c) The frequency of vibrations is less than the natural frequency(d) There is no presence of resistive force

Ans. (c)

Explanation:
Damped vibrations refer to oscillations or vibrations that decrease in amplitude over time due to the presence of a resistive force, such as friction or drag. The resistive force acts against the motion of the vibrating system and causes the energy of the system to be gradually dissipated as heat or other forms of energy, leading to a reduction in amplitude.

#### (a) upto 240 dB(b) upto 120 dB(c) upto 30 dB(d) upto 500 dB

Ans. (b) upto 120 dB
Explanation:
The safe limit of sound level for human ears is typically considered to be 85 decibels (dB) for an exposure of 8 hours per day. Prolonged exposure to sounds at or above this level can lead to noise-induced hearing loss. It's important to note that as the sound level increases, the safe exposure time decreases. For example:

• At 88 dB, safe exposure is limited to 4 hours.
• At 91 dB, safe exposure is reduced to 2 hours.
• At 100 dB, safe exposure is only 15 minutes.

#### Q3.  Which phenomenon is involved in tuning a radio set to a particular station?

Explanation:
Various frequencies from many radio stations are impinging on the antenna of the radio set at the same time. To tune exactly a radio receiver, we just adjust the settings indicated on the electrical components in the manner that vibrations of the exact same frequency of the radio waves we wish to receive are generally produced. When both the frequencies match because of resonance, the energy of the signal at that frequency is received from the incoming waves. Thus, resonance is the main phenomenon, which is involved in tuning a radio set to a particular station.

#### Q4. Write one example for:(i) Natural Vibration(ii) Forced vibration(iii) Resonance

Explanation:
Examples are as follows:

• Natural vibration : The vibration of a simple pendulum about its mean position.
• Forced vibration : A sonometer wire under tension , vibrating under the influence of a vibrating tuning fork.
• Resonance : A correctly adjusted length of a sonometer wire under proper tension, vibrating under the influence of a vibrating tuning fork.

#### Q5. Suppose that we take a guitar to the moon and play it. What do you think will happen.?

Explanation:
There is vacuum on the moon.There is no force acting on the string which will resist its motion.If we displace the string once,it will vibrate for infinitely because of restoring force.This type of vibration shown by the string is called natural or free vibration.

#### ICSE Class 10 Physics Chapter wise Important Questions

Chapter No. Chapter Name
Chapter 1 Force Work Power and Energy
Chapter 2 Simple Machines
Chapter 3 Refraction of Light
Chapter 4 Refraction Through Lenses
Chapter 5 Spectrum
Chapter 6 Vibrations of Sound
Chapter 7 Sound
Chapter 8 Electricity
Chapter 9 Electrical Power and Household Circuits
Chapter 10 Magnetic Effect of Current
Chapter 11 Specific Heat Capacity and Latent Heat
Chapter 12 Radioactivity and Nuclear Energy

#### Conclusion

The behavior of sound, including reflection, refraction, interference, and resonance, serves as a tangible and audible representation of fundamental wave principles. These behaviors are pivotal in fields such as architectural acoustics, where the design of spaces hinges on the optimal propagation and absorption of sound. For those looking for extra practice and a better grasp of the chapter's concepts, oswal.io provides a wide range of sound class 10 ICSE questions and answers, allowing for a more in-depth comprehension of the subject matter

#### Q1 : What is the difference between pitch and frequency?

Ans: Frequency is a measurable quantity that represents the number of oscillations or vibrations per second, measured in Hertz (Hz). Pitch, on the other hand, is a perceptual attribute of sound. It's how we perceive the highness or lowness of a sound. Generally, higher frequency sounds are heard as higher pitched.

#### Q2 : What is resonance in terms of sound?

Ans:  Resonance is a phenomenon where an object starts to vibrate at its natural frequency when exposed to an external sound of the same frequency. This amplifies the sound. A classic example is a wine glass shattering when a singer hits the right note.

#### Q3 : How do musical instruments produce sound?

Ans: Musical instruments produce sound by creating vibrations. For example, a guitar produces sound when its strings vibrate, a drum when its membrane is struck, and a flute when air is blown over its holes.

#### Q4 : What causes an echo?

Ans:  An echo is caused by the reflection of sound waves. When sound waves hit a hard and large surface, they bounce back. If there's enough time delay between the original sound and its reflection (typically 0.1 seconds or more), we perceive it as an echo.

#### Q5 : What's the significance of ultrasound in physics?

Ans: Ultrasound refers to sound waves with frequencies above the audible range for humans (typically above 20,000 Hz). In physics and its applications, ultrasound is used in medical imaging (like sonograms), therapeutic treatments, and for measuring distances underwater (SONAR).

## Chapter Wise  Important Questions for ICSE Board Class 10 Physics

###### Copyright 2022 OSWAL PUBLISHERS Simplifying Exams
Phone:  (+91) 78959 87722
Mail: support@oswalpublishers.in