Question:
Fill in the blanks :
Number of oscillations completed by the oscillator in one second is known as ___________.
Sound
Q 1.
Fill in the blanks :
If a body repeats its back and forth, to and fro or up and down motion along a certain path, about a fixed point, in a certain time interval then the motion of such objects is said to be _____________.
Q 2.
What is speed of sound in air?
Q 3.
Fill in the blanks :
The principle on which stethoscope works is _____ (reflection/ multiple reflection)
Q 4.
What type of wave is represented by density- distance graph?
Q 5.
Distinguish between loudness and intensity of sound.
Q 6.
What is Sound? Why it is important for us?
Q 7.
Fill in the blanks :
In the case of ____________ wave, distance between two consecutive crests or troughs is known as wavelength.
Q 9.
What are ultrasonics?
Q 10.
How is ultrasound used for cleaning ?
Q 11.
Fill in the blanks :
RADAR (Radio Detection And Ranging) works on _____________ principle which is used to determine the velocities and movement of aircrafts.
Q 12.
What are wavelength, frequency, time period and amplitude of a sound wave?
Q 13.
What is reverberation?
Q 14.
Draw a curve showing density or pressure variations with respect to distance for a disturbance produced by sound.Mark the position of compression and rarefaction on this curve.Also define wavelengths and time period using this curve.
Q 15.
What is audible range ?
Q 16.
How can you make a building sound proof ?
Q 17.
Why are the ceilings of concert halls curved ?
Q 18.
What is sound barrier ?
Q 19.
A wave of wavelength 0-60 cm is produced in air and it travels at a speed of 300 m/s.Will it be audible ?
Q 20.
Radio Ceylon broadcasts at 25 m.What is the frequency of the station ?
Q 21.
Cite an experiment to show that sound needs a material medium for its propagation.
Q 22.
What is loudness of sound ? What factors does it depend on ?
Q 24.
What are transverse waves ?
Q 25.
What is SONAR ? How is it used to detect an underwater object and measure its distance
Q 26.
Fill in the blanks :
A ________ (pulse/wave) is a disturbance which is sudden and lasts for a short duration of time.
Q 27.
Fill in the blanks :
In a __________ wave the particles of the medium oscillate in a direction perpendicular to the direction in which the wave propagates.
Q 28.
Fill in the blanks :
The distance between two consecutive compressions or two consecutive rarefactions is called the ______________.
Q 29.
What is a mechanical wave?
Q 30.
Why sound waves are called mechanical waves?
Q 31.
How are the wavelength and frequency of a sound wave related to its speed?
Q 32.
A sound wave travels at a speed of 339 ms
–1. If its wavelength is 1.5 cm, what is the frequency of the wave?
Q 33.
What is infrasonic? Give an example.
Q 34.
An engine is approaching a hill at constant speed.When it is at a distance of 0.9 km,it blows a whisde,whose echo is heard by the driver after 5 s.If the speed of sound is 340 m/s,calculate the speed of the engine.
Q 35.
Guess which has a higher pitch : a guitar or a car horn ?
Q 36.
Distinguish between loudness and intensity of sound.
Q 37.
What is sound and how is it produced ?
Q 38.
The frequency of a source of sound is 100 Hz.How many times does it vibrate in a minute ?
Q 40.
What is the minimum distance of the obstacle from the source of sound for hearing distinct echo ?
Q 41.
What is sound ? Discuss the method of its production.
Q 42.
What do you mean by reverberation and reverberation time ? How is reverberation controlled ?
Q 43.
Deaf people can be made to dance to music.Explain how ?
Q 44.
Fill in the blanks :
If a body repeats its motion, within fix interval of time, along a certain path, about a fixed point, it is said to have ____________.
Q 45.
Fill in the blanks :
Sound, compressional waves in springs are examples of _____________.
Q 46.
Fill in the blanks :
Loudness of sound is measured in ___________.
Q 47.
What type of waves can travel in vacuum? Give example(s).
Q 48.
What is a wave number?
Q 49.
A hospital uses an ultrasonic scanner to locate tumors in a tissue. What is the wavelength of sound in a tissue is which the speed of sound is 1.7 km/s. The operating frequency of the scanner is 4.2 MHz. (1MHz = 10
6 Hz).
Q 50.
Which wave characteristics determine the
(a) Loudness (b) pitch of sound?
Draw two different waveforms and mark these characteristics on it.
