MEDIUM
7th CBSE
IMPORTANT
Earn 100

List the following persons in ascending order, according to the shrillness in their voice.

(a) A woman of age 40

(b) A man of age 40

(c) A 5 th class girl

(d) An infant baby

Important Questions on Sound

MEDIUM
7th CBSE
IMPORTANT
Pearson IIT Foundation Physics>Chapter 5 - Sound>PRACTICE QUESTIONS (COMPETITION WING)>Q 78
A ship at rest is sending ultrasonic sound waves to detect a shoal of fish. If the time gap between the signal sent from the ship and received (reflected) signal is 0.5 s, then find the distance of the shoal of fish from the ship. (Velocity of sound in water is 1400 m s-1)
MEDIUM
7th CBSE
IMPORTANT
Pearson IIT Foundation Physics>Chapter 5 - Sound>PRACTICE QUESTIONS (COMPETITION WING)>Q 79
Why are the walls, roof, seats, and steps, of a cinema theatre or auditorium covered with special material?
 
MEDIUM
7th CBSE
IMPORTANT
Pearson IIT Foundation Physics>Chapter 5 - Sound>PRACTICE QUESTIONS (COMPETITION WING)>Q 80
Why are concave reflectors used in big auditoria?
MEDIUM
7th CBSE
IMPORTANT
Pearson IIT Foundation Physics>Chapter 5 - Sound>PRACTICE QUESTIONS (COMPETITION WING)>Q 81
The audible range of frequency is 20 Hz to 20,000 Hz. Determine the corresponding range of time periods of vibrations.
MEDIUM
7th CBSE
IMPORTANT
Pearson IIT Foundation Physics>Chapter 5 - Sound>PRACTICE QUESTIONS (COMPETITION WING)>Q 82
A bat entering into a well finds it difficult to come out of it. Explain the reason.
MEDIUM
7th CBSE
IMPORTANT
Pearson IIT Foundation Physics>Chapter 5 - Sound>PRACTICE QUESTIONS (COMPETITION WING)>Q 83
Ramu and Numu are celebrating Diwali with crackers when Ramu fired a cracker after looking at the lighting Numu started counting seconds hand movement in his watch at 8.00 pm and he stopped counting when he heard the cracker sound at 08:00:02 pm. Find the distance between Ramu and Numu if the speed of the sound is 310 m s-1.
MEDIUM
7th CBSE
IMPORTANT
Pearson IIT Foundation Physics>Chapter 5 - Sound>PRACTICE QUESTIONS (COMPETITION WING)>Q 84
A student breaks a fused bulb, and then hears a sound of explosion. What could be the reason for this? Explain.
MEDIUM
7th CBSE
IMPORTANT
Pearson IIT Foundation Physics>Chapter 5 - Sound>PRACTICE QUESTIONS (COMPETITION WING)>Q 85
How are dogs made alert by the crime department? Explain.