Download 10th Class Physics Notes (Unit # 11) for Federal Board (FBISE) Islamabad

Download 10th Class Physics Notes (Unit # 11) for Federal Board (FBISE) Islamabad.

Very Easy, Updated & Comprehensive Notes for all types of students i.e. Average / Extra Ordinary
Note: 
  • Please subscribe our SMS Alerts Service, Email Updates or Like our Facebook Page from right sidebar to get latest updates regarding our notes & other materials.
  • You can also install our Mobile App to view/read our notes anytime, anywhere on mobile.
  • Please inform us regarding any correction/mistake (if found) by Contacting Us.
  • Please SHARE this page from below, if you liked these Notes.

Download 10th Class Physics Notes for Federal Board (FBISE) Islamabad
SHORT QUESTIONS

What is the necessary condition for the production of sound? In which medium sound travels fast? Air, solid or liquid Justify your answer.
Sound wave can be produced by vibrating a body. It travels in a medium whose particles can vibrate. The frequency of vibrations must be greater than 20Hz and less than 20,000Hz. In solids the sound waves have faster speed than in air or liquid (due to larger elasticity).
What is the effect of the medium, on the speed of sound? In which medium sound travels more faster: air, solid or liquid? Justify your answer.
Sound waves are mechanical waves so medium has effect on the speed of sound waves. In solids the sound waves have faster speed than in air or liquid (due to larger elasticity).

How can you prove the mechanical nature of sound by a simple experiment?
·         The sound waves are "mechanical waves". It require material medium.
·         It can be proved by placing an electric bell inside a glass jar where vacuum is produced.
·         The electric bell is made ON, but its sound cannot be heard, due to vacuum and no material medium.
·         While before producing vacuum sound will be heard.
What do you understand, by the longitudinal wave? Describe the longitudinal nature of sound wave.
·         The waves are said to be longitudinal if the particles of the medium vibrate in the same direction as the direction of propagation of waves.
·         Sound waves are mechanical and longitudinal in nature.
·         It means the particles of the medium (air, liquid or solid) vibrate in the same direction as the direction of the sound waves travel.

Sound is a form of wave. List at least three reasons to support the idea that sound is a wave.
Sound is a form of wave.
  • It gives the sensation of hearing. If we listening sound the membrane of our ear starts vibrating.
  • Ultra -sounds (high energy waves) are used in medical sciences.

We know that waves manifest phenomenon of reflection, diffraction and refraction. Does sound also manifest these characteristics
  • Yes, sound waves also exhibit the characteristics like reflection, diffraction and refraction.
  • Echo is the practical example for the reflection of sound waves.
  • Listening of the person in other room is an example of diffraction of sound waves.
  • There are example to show the refraction of sound waves by which their speed and direction is change.
What is the difference between the loudness and intensity, of sound? Drive the relation between them OR Define Weber-Fechner law.
Loudness:
It is a characteristic of sound by which loud and faint sounds can be distinguished.
Intensity:
Sound energy flowing per second through a unit area held perpendicular to the direction of sound waves is called the intensity of sound.
Relation:
L       α      log I
L       =      (Constant) log I
L       =      k log I
This equation is mathematical representation of Weber-Fechner law. Here K is constant of proportionality.

On what factors does the loudness of sound depend?
a.           Amplitude of Vibrating Body: -
·         If amplitude of vibrating body is large then loud sound will be produced and if amplitude is small then faint sound will be produced
·         e.g. when we strike the drum forcefully loud sound will be produced due to large amplitude.
b.           Area of Vibrating Body: -
·         If the area of vibrating body is larger than loud sound will produced and if the area of vibrating body is small then faint sound will produced
·         e.g. sound produced by larger drum will be loud then a small drum.
c.           Distance from vibrating body: -
·         Loudness of sound also depends upon the distance between producer and listener.
·         Greater distance between them result in faint sound.
·         Less distance between them results in loud sound.

What do you mean by the term intensity level of the sound? Name and define the unit of intensity level of sound.
Difference between loudness of sound and loudness of faintest sound is called intensity level for any sound. The unit of intensity level is bel. The smaller unit of intensity level is decibel and 1 bel = 10 dB.
Intensity Level = 10 log I/Io dB

What are the units of loudness? Why do we use logarithmic scale to describe the range of the sound intensities we hear?
The unit of loudness is bel. The smaller unit is decibel.
What is difference between frequency and pitch? Describe their relationship graphically.
The number of wave lengths passing through a point in one second is called frequency. Its units are hertz (HZ) and, the pitch is quality of sound due to which a shrill and grave voice can be distinguished. The greater is frequency of sound, the larger is pitch of sound and vice -versa.
Describe the effect of change in amplitude on loudness and the effect of change in frequency on pitch of sound. Does sound also manifest these characteristics?
The effect of change of amplitude of sound waves the energy changes and due to which loudness may also change.
The magnitude of sensation of sound is called "loudness". When frequency of sound wave affect the pitch of sound waves. The greater is frequency, the larger is it pitch and vise -versa.
If we clap or speak in front of a building while standing at a particular distance, we rehear our sound after sometime. Can we explain how does this happen?
It is due to the reflection of sound waves. After incident on the walls of they come back into the same medium. That is why we rehear the sound after some time. It is called echo.

What is the audible frequency range for human ear? Does this range vary with the age of people? explain.
As name indicates, it is a range of sound’s frequency, which a person can hear. A human ear can hear a sound only if its frequency lies between 20 and 20,000 hertz (Hz). If the frequency of sound is less or greater than this range then that sound is in-audible and could not be heard. This range can be slightly differs in different persons.

Explain that noise is a nuisance.
The sound which produce jarring and unpleasant effect on our ears are called noise. Noise pollution is a serious issue. Noise has negative effects on human health as it can cause conditions such as hearing loss, sleep disturbance, aggression, hypertension, high stress levels.

Describe the importance of acoustic protection.
In the construction of classrooms, halls and musical halls if the walls are too absorbent then sound level will low and hall will sound dull and lifeless. There should be balance between reverberation and absorption. It is often advantageous to place reflective surfaces behind the stage to direct sound to the audience. The ceiling of lecture and conference halls are curved so that sound after reflection may reach all the corners of the hall.

What are the uses of ultrasound in medicine?
  • Ultrasonic waves are used to diagnose and treat different diseases. The waves are made to enter the patient body through transmitters. These waves are reflected differently by different organs, tissues etc. The reflected waves are amplified to form image which help in detecting the defect in the organs.
  • Powerful ultrasound is being used to remove blood clots formed in the arteries.
  • Ultrasound is used to get the picture of thyroid gland for diagnosis purposes.


What are uses of ultrasound in technical fields?
  • Cracks appear in the interior of moving parts of high speed and heavy machines such as turbines, engine of ships and airplanes. These cracks are not visible but can be detected by ultrasound.
  • Germs and bacteria in liquids can also be destroyed by using high intensity ultrasonic waves.
Why two tin cans with a string stretched between them could be better way to communicate than merely shouting through the air.
It is better way to communicate because the sound waves have high speed in solids than air and also maximum intensity (energy) will be transferred through string. While in case of air speed is slow and intensity will be spread over large area.
We can recognize persons speaking with the same loudness from their voice. How is this possible?
We can recognize the persons sound having the same loudness because of the quality of the sound, are pitch.
You can listen your friend round a corner, yet you cannot watch him/her. Why?
The sound waves have larger wave length than light. These are diffracted by corner of well and light waves cannot do so, due to their very small wave length (as compared with size of wall corner). So, without seeing the friend his/ her voice can be heard.
Why must the volume of it stereo in a room with wall -to -wail carpet be turned higher than in a room with a wooden floor?
The wooden floor is more rigid than carpet. The sound waves produce reverberations after reflecting from rigid wooden floor. Therefore, volume of the stereo must be kept smaller. Whereas, in case of carpet this is not the case and waves are mostly absorbed.
A student says that the two terms speed and frequency of the wave refer to the same thing. What is your response?
We know the relation between speed, frequency and wavelength V     =f λ. It shows that speed depends upon frequency and vice versa. But it is not necessarily because in case of refraction of sound waves speed changes by changing only the wavelength.
Two people are listening to the same music at the same distance. They disagree on its loudness. Explain how this could happen.
The two persons listening some same sound, sitting at same distance away from the source, can say that loudness is not same, because the different human ears have different sensitivities.
Is there any difference between echo and reflection of sound? Explain
Reflection:
The process, when sound waves incident on the surface of a medium it bounces back into the first medium, is called reflection of sound waves.
Echo:
Echo is the same of reflection of sound waves but due to sensation of sound persists in our brain for 0.1 sec. To hear echo the time interval between our sound and reflected sound must be at least 0.1 sec. As we know the speed of sound is 334 ms-I at STP. Then to hear echo the minimum distance between obstacle and from the source of sound must be 17m.
Will two separate 50 dB sound together constitute 100dB sound? Explain
Decibel is unit of intensity level. Whose value depends upon the natural loge of intensities of a sound to the intensity of ordinary conversation. Therefore 50dB sound, coming from two sources can not constitute 100 dB sound.

Why ultrasound is useful in medical field?
Ultrasound are harmless energetic sound waves, that is why these are useful in medical field.

How does Stethoscopes operate?
It works on the transmission of sound for the chest piece, via air filled hollow tubes, to the listener’s ears. The chest piece usually consists of a plastic disc called diaphragm. If the diaphragm is placed on the patient’s body sounds vibrate the diaphragm, creating acoustic pressure waves which after multiple reflection travel up the tubing to the doctor’s ears.

What is sound? How it is produced and travel?
Sound is form of energy. It is produced by vibration of bodies. It travels in the form of pressure waves from one place to another.

Why silent whistle is used to call dogs?
Some people use silent whistle to call dogs whose frequency lies between 20,000Hz to 25,000Hz. It is silent for human bug not for dogs. Because the audible frequency range for dogs is much higher.

On which things frequency of tuning fork depends?
Frequency of tuning fork depends on the mass of its prongs. The greater the mass, the lower the frequency of vibration which means the lower the pitch.

How whales can communicate over hundreds & thousands miles?
This is possible in part because sound waves travel five times faster in water than in air. In addition, the temperature characteristics of ocean water – decrease in temperature with depth – create a unique sound phenomenon.

What is the function of large ears of elephants?
Elephants use low frequency sound waves to communicate with one another. Their large ears enable them to detect these low frequency sound waves, which have relatively long wavelengths. Elephants can effectively communicate in this way, even when they are separated by many kilometers.

What are the audible frequency ranges of bats, mice, dogs & cats and humans?
Bats can hear frequencies up to 120,000 Hz. Other animals cannot hear such high pitched sounds. Mice can hear frequencies up to 100,000Hz, dogs upto 35,000Hz and cats upto 25,000Hz and human upto 20,000Hz.

How can you see sound waves?
By using oscilloscope, we can see sound waves.

What are infrasonics?
The sound waves of frequency less than 20Hz are called infrasonics.

What is Sonar. Explain.
  • SONAR stands for Sound navigation and ranging.
  • It is technique to find depth of ocean and to locate the objects lying deep in the ocean. The ultrasound waves are sent from a transmitter and receiver collects the reflected waves. The time lapse is calculated, knowing the speed of sound in water the distance can be determined.
  • SONAR ranging is also used to see the shape and size of objects, in side water.
                                
LONG QUESTIONS

Show with the help of experiment that sound waves are mechanical waves.
Sound waves require some medium for their propagation. So we can say that sound waves are mechanical waves.
Propagation of sound – Experiment:
·         Place a bell jar on vacuum pump.
·         Suspend an electric bell in it with the help of two wires.
·         Fix a cork in the mouth of bell jar.
·         On ringing the bell sound can be heard.
·         Now start expelling the air form jar by vacuum pump.
·         The sound becomes faint and faint.
·         At last sound become hardly heard.
·         By this experiment it has proved that medium is necessary for propagation of sound waves.

Write down the characteristics of sound?
There are following characteristics of sound: -
i)           Loudness: -
It is a characteristic of sound by which loud and faint sounds can be distinguished.
Loudness of sound depends upon following factors: -
d.           Amplitude of Vibrating Body: -
·         If amplitude of vibrating body is large then loud sound will be produced and if amplitude is small then faint sound will be produced
·         e.g. when we strike the drum forcefully loud sound will be produced due to large amplitude.
e.           Area of Vibrating Body: -
·         If the area of vibrating body is larger then loud sound will produced and if the area of vibrating body is small then faint sound will produced
·         e.g. sound produced by larger drum will be loud then a small drum.
f.            Distance from vibrating body: -
·         Loudness of sound also depends upon the distance between producer and listener.
·         Greater distance between them result in faint sound.
·         Less distance between them results in loud sound.

ii)         Intensity of Sound: -
·         Sound energy flowing per second through a unit area held perpendicular to the direction of sound waves is called the intensity of sound.
·         It is physical quantity and does not depend on the condition of ear.
iii)       Pitch of Sound: -
·         The characteristic of sound by which a shrill sound and grave sound can be distinguished.
·         Higher pitch shows lower frequency.
·         Frequencies of voices of ladies and children are greater and their voice is shrill.
·         The frequencies of old men are lesser and their sound is grave.
iv)        Quality of Sound: -
The characteristics of sound by which two sounds of same loudness and pitch can be distinguished.
v)          Noise & Music: -
·         The sound, which has pleasant effect on our ears, is called Music.
·         The sound, which produces jarring effect on our ears, is called noise.


COMMENTS

Name

10th Class Notes,72,10th Class Old Papers,2,5th Class Notes,6,6th Class Notes,34,6th Class Old Papers,1,7th Class Notes,33,7th Class Old Papers,1,8th Class Notes,63,8th Class Old Papers,1,9th Class Notes,82,9th Class Old Papers,2,Articles,1,Download Free E-Books on IT,1,Home Tutors,3,Home Tutors in Islamabad & Rawalpindi,8,Home Tutors in Lahore,2,Home Tutors in Multan,1,Home Tutors in Wah Cantt & Taxila,3,Information Technology,1,Miscellaneous,10,News & Events,2,Notes & Handouts,292,Old Papers,8,Solved AIOU Assignments,1,Video Lectures,1,
ltr
item
Download Class Notes: Download 10th Class Physics Notes (Unit # 11) for Federal Board (FBISE) Islamabad
Download 10th Class Physics Notes (Unit # 11) for Federal Board (FBISE) Islamabad
Download 10th Class Physics Notes (Unit # 11) for Federal Board (FBISE) Islamabad
https://3.bp.blogspot.com/-nk4LF25WL8g/WKFJHmac6KI/AAAAAAAADZc/fHTIAdAFJkwMibOEM7lmpTdWcEFMqOLAQCLcB/s1600/10th_class_physics_notes_fbise_islamabad_by_shahzad_iftikhar.jpg
https://3.bp.blogspot.com/-nk4LF25WL8g/WKFJHmac6KI/AAAAAAAADZc/fHTIAdAFJkwMibOEM7lmpTdWcEFMqOLAQCLcB/s72-c/10th_class_physics_notes_fbise_islamabad_by_shahzad_iftikhar.jpg
Download Class Notes
http://www.downloadclassnotes.com/2016/10/unit-11-download-10th-class-physics-notes-federal-board-fbise-islamabad.html
http://www.downloadclassnotes.com/
http://www.downloadclassnotes.com/
http://www.downloadclassnotes.com/2016/10/unit-11-download-10th-class-physics-notes-federal-board-fbise-islamabad.html
true
6576910405746451012
UTF-8
Loaded All Posts Not found any posts VIEW ALL Readmore Reply Cancel reply Delete By Home PAGES POSTS View All RECOMMENDED FOR YOU LABEL ARCHIVE SEARCH ALL POSTS Not found any post match with your request Back Home Sunday Monday Tuesday Wednesday Thursday Friday Saturday Sun Mon Tue Wed Thu Fri Sat January February March April May June July August September October November December Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec just now 1 minute ago $$1$$ minutes ago 1 hour ago $$1$$ hours ago Yesterday $$1$$ days ago $$1$$ weeks ago more than 5 weeks ago Followers Follow THE DOWNLOAD LINK IS LOCKED Please share to unlock the download link Copy All Code Select All Code All codes were copied to your clipboard Can not copy the codes / texts, please press [CTRL]+[C] (or CMD+C with Mac) to copy