LEARN 8TH GRADE

1. PREPARED BY: VARUN AND AIYAN
PHYSICS-SOUND CHAPTER

2. RULES
 NO MASS ANSWERING
 ONLY LEADERS CAN TELL WHO IS GOING TO TELL IN THEIR GROUP &
ONLY HE CAN CHOOSE THE TOPIC AND THE POINT
 NO ONE IS ALLOWED TO DISCUSS
 IF TALKING -25 FROM THE TOTAL
 NO RAISING THEIR HANDS
 PLZ OBEY IT!!!

3. Jeopardy
$100
Topic 1 Topic 2 Topic 3 Topic 4
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Final Jeopardy

4. 1 - $100
 SOUND TRAVELS IN THE FORM OF__________.
 WAVES

5. 1 - $200
 SI UNIT OF FREQUENCY AND LOUDNESS ?
 Hertz and Decibel

6. 1 - $300
 A mixture of sounds or other frequencies ?
 harmonics

7. 1 - $400
 What is sound?
 Sound is a form of energy which produces a
sensation of hearing in our ears.

8. 1 - $500
 Explain the structure of human ear?
 OUTER EAR: IT CONSISTS OF A FLAP-LIKE STRUCTURE CALLED
PINNA ONE ON EACH SIDE OF YOUR FACE.THE PINNA IS
FURTHER CONNECTED TO EAR CANAL, AT THE END OF WHICH
THE EAR DRUM IS PRESENT. EAR DRUM IS A STRETCHED
MEMBRANE THAT SEPARATES THE OUTER EAR FROM THE
MIDDLE EAR.
 MIDDLE EAR:IT CONSISTS A CHAIN OF 3 BONES:- HAMMER,
ANVIL, AND STIRRUP. HAMMER IS CONNECTED TO THE EAR
DRUM AND THE INNER MOST BONE OR STIRRUP IS
CONNECTED TO THE INNER EAR.
 INNER EAR: THE INNER EAR CONTAINS COCHLEA AND SEMI-
CIRCULAR CANALS. COCHLEA IS SPIRALLY-COILED TUBE AND
LOOKS LIKE A SNAIL SHELL. IT IS FILLED WITH A FLUID AND
HAS MANY HAIR CELLS INSIDE IT. THEN THE IMPULSES ARE
SENT TO THE BRAIN THROUGH AUDITORY NERVES.

9. 2 - $100
 What is meant by time period of a pendulum?
 The time taken by the bob of a pendulum to
complete 1 oscillation is called the time period of
a pendulum.

10. 2 - $200
 WHAT IS REED INSTRUMENT
 REED INSTRUMENTS CONTAIN METAL REEDS
WHICH PRODUCE SOUND WHEN AIR IS BLOWN
THROUGH THEM.

11. 2 - $300
 THE PITCH OF THE SOUND PRODUCED BY AN
OBJECT VIBRATING WITH LOW FREQUENCY IS
LOW AND THE SOUND IS
CALLED___________/_________ SOUND
 SHRILL/FLAT

12. 2 - $400
 WHAT IS VIBRATION?
 A VIBRATION IS A RAPID BACK AND FORTH
MOVEMENT OF AN OBJECT ABOUT ITS MEAN
POSITION.]

13. 2 - $500
 DEFINE
 AUDIBLE,INFRASONIC AND ULTRASONIC
SOUND
 THE SOUND WHOSE FREQUENCY LIES
BETWEEN 20 Hz AND 20,000Hz WHICH WE ARE
ABLE TO HEAR.
 THE SOUND WHOSE FREQUENCY IS LESS THAN
20 Hz IS CALLED INFRASONIC AND THE SOUND
WHOSE FREQUENCY IS MORE THAN 20,000Hz
IS CALLED ULTRASONIC SOUND.

14. 3 - $100
 QUALITY OF SOUND IS -----
 TONE

15. 3 - $200
 0.1 SECONDS
THE REFLECTED SOUND WHICH CAN BE HEARD
DISTINCTLY(AFTER A LAPSE OF ATLEAST _____ SECONDS). FROM
THE ORIGINAL SOUND BY HUMAN EARS IS CALLED ECHO

16. 3 - $300
 IDENTIFY THE PERSONALITY
 Heinrich Hertz

17. 3 - $400
 IDENTIFY THE INSTRUMENT AND ITS TYPE
 SHEHNAI,WIND INSTRUMENT

18. 3 - $500
 Type question to appear here
PINNA
COCHLEA
HAMMER
ANVIL
STIRRUP
EAR CANAL

19. 4 - $100
 UNWANTED , UNPLEASANT AND VERY LOUD
SOUND ARE CALLED____________-
 NOISE

20. 4 - $200
 Which country students use
this gloves?
 Ukraine ( read pg number 193 in tb science
update)

21. 4 - $300
 HEINRICH IS HONORED IN THE SI UNIT
OF_____________
 FREQUENCY

22. 4 - $400
 Give a example of source of sound which is only
10 dB and very faint…
 Rustling of leaves

23. 4 - $500
Explain the sound
produced by
humans?

24. Final Jeopardy
 THESE THREE BONES ARE NAMED ACCORDING
TO THEIR SHAPES AND ARE COLLECTIVELY
CALLED ___________________.
 OSSICLES

25. THANK YOU
 THANK YOU FOR OBEYING