10th physics Short Questions

1. Class 10th
Subject : Physics
Unit:11
Sound
Prepared BY ; Umar Tabraiz

2.  The Frequency
With the Increase of the Pitch of Sound the Frequency also
Increase
Pitch of sound ∝ Frequency of Sound

3.  As Frequency and pitch of sound are directly proportional to
each other so wavelength decrease with increase of pitch of
the sound .
v = f λ
λ = v / f
Since Frequency is increases with increase of pitch,
then wavelength (λ) decrease .

4.  Wave velocity increase with increase the pitch of sound
v = f λ
If wavelength of sound kept constant with high frequency ,
speed of sound (v) will increase
Wavelength can be defined as the distance between two
successive crests or troughs of a wave

5.  Amplitude does not change as it is
independent of the pitch of sound and its
frequency also.

6.  It is due to reflection of sound . After incident on the walls,
they come back into the same medium .
 That is why we rehear the sound after some time .
 It is called echo ( Reflection of sound wave )

8.  Audible frequency range for human lies between
20 Hz to 20,000 Hz .
 It decrease with age
 In old people this range is up to 15,000 Hz

9.  The sound which produce jarring and unpleasant effect on
our ear is called noise.
 Noise pollution is a serious issue .
 Noise has negative effect on our health as it can cause
conditions such as Hearing loss , Sleep Disturbance ,
hypertension , High level stress .

12.  The absorbing of undesirable sound by soft or porous material
is called Acoustics.
 Reflection of sound is more prominent if the surface is rigid
and smooth
 Reflection of sound is less if the surface is soft and irregular.
 If the surface of class rooms and public halls are to absorbent
, then sound level is low for audience
 The lecture and conference hall are curved so that sound
after reflection may reach all the corner of the hall.
 Reflective surface behind the stage are help to direct sound
to the audience .

16.  Ultrasound waves are used to diagnose and treat different
diseases.
 Powerful ultrasound is used to remove blood clots formed in
arteries.
 Ultrasound is used to get the picture of thyroid gland for
diagnoses purpose.
 Blood flow can also be monitored by ultrasound.
 Detection of tumors