MEDIUM
9th CBSE
IMPORTANT
Earn 100

Assertion: Ultrasonic sound is used in industry for detecting flaws (cracks etc) in metal blocks without damaging them.
Reason: An internal crack (or hole) does not allow ultrasound to pass through it.

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Important Questions on Sound

MEDIUM
9th CBSE
IMPORTANT
All In One SCIENCE CBSE Class IX>Chapter 12 - Sound>CHAPTER EXERCISE>Q 9
What is the nature of the ocean waves in deep water?
MEDIUM
9th CBSE
IMPORTANT
All In One SCIENCE CBSE Class IX>Chapter 12 - Sound>CHAPTER EXERCISE>Q 10
What will increase, if we change feeble sound to loud sound?
MEDIUM
9th CBSE
IMPORTANT
All In One SCIENCE CBSE Class IX>Chapter 12 - Sound>CHAPTER EXERCISE>Q 11
Which physical quantity remains unchanged after reflection of sound wave?
EASY
9th CBSE
IMPORTANT
All In One SCIENCE CBSE Class IX>Chapter 12 - Sound>CHAPTER EXERCISE>Q 12
Give the principle involved in megaphone.
EASY
9th CBSE
IMPORTANT
All In One SCIENCE CBSE Class IX>Chapter 12 - Sound>CHAPTER EXERCISE>Q 13
The window panes of houses sometimes crack when bomb explodes even at a large distance. Why?
MEDIUM
9th CBSE
IMPORTANT
All In One SCIENCE CBSE Class IX>Chapter 12 - Sound>CHAPTER EXERCISE>Q 14
How do submarines know the depth of a sea?
EASY
9th CBSE
IMPORTANT
All In One SCIENCE CBSE Class IX>Chapter 12 - Sound>CHAPTER EXERCISE>Q 15
What is compression and rarefaction in longitudinal wave? Explain.
MEDIUM
9th CBSE
IMPORTANT
All In One SCIENCE CBSE Class IX>Chapter 12 - Sound>CHAPTER EXERCISE>Q 16
Why does the amplitude of oscillation get reduced over a period of time? Explain with diagram.