PHYSICS [1 Mark Question Answer]

Echo is the sound heard after reflection from a rigid surface such as a cliff, a hillside, the wall of a building etc.

The reflection of sound is used in making the speaking tube (or megaphone), sound board and trumpet.

Reflection of Sound— When a sound wave strikes a rigid surface, it retraces from its path is called reflection of sound.

Sound travels with the highest speed in - solids.
and Sound travels with the lowest speed in - gases.

In a piano, the string is struck to make the string vibrate and produce sound. The pitch of sound produced can be changed by stretching or loosening the strings of piano.

The stringed instruments are provided with a number of strings of different thickness and under different tensions so that each string produces sound of a different pitch.

Sound is produced by vibrating bodies.

In musical instruments like flute and clarinet, the pitch of sound is changed by changing the length of vibrating air column when different holes in it are closed.

It is the pitch and quality that helps a musician recognize the musical instrument by hearing the sound produced by it, even without seeing the instrument.

We can recognize our friend by hearing his voice on a telephone due to quality of sound and pitch of sound.

The quality is the characteristic of sound which distinguishes the two sounds of the same pitch and same loudness.

Higher the pitch, the shriller is the sound. Lower the pitch, the flat (or grave) is the sound.

The pitch of a sound depends on its frequency (i.c., on the frequency of the vibrating body).

The outer case of the bell in a temple is made big. So that there is multiple reflection of sound and the sound can be amplified.

Sound is a form of energy which produces the sensation of hearing.

The loudness of a sound depends on the amplitude of vibration of the vibrating body producing the sound.

Sounds of frequency lower than 20 Hz are called the infrasonics. We cannot hear the infrasonic sounds.

Sounds of frequency higher than 20,000 Hz are called the ultrasonics. We cannot hear the ultrasonic sounds.

The range of frequency from 20 Hz to 20,000 Hz is called the audible range for the normal human ear.

Frequency or u Number of oscillations made by a wave in one second is known as its frequency.

In a longitudinal wave, the particles of air vibrate to and fro about their mean positions in the direction of travel of sound.

No, we cannot hear each other since sound requires medium for transmission. It cannot travel through vacuum.

The oscillatory motion in which the body assumes a new shape during its motion, is called the vibratory motion.