SOUND : NCERT Exemplar

 

Multiple Choice Questions

Q.1 Note is a sound

(a) Of mixture of several frequencies

(b) Of mixture of two frequencies only

(c) Of a single frequency

(d) Always unpleasant to listen

Sol. (a) 

Q.2 A key of a mechanical piano struck gently and then struck again but much harder this time. In the second case

(a) Sound will be louder but pitch will not be different

(b) Sound will be louder and pitch will also be higher

(c) Sound will be louder but pitch will be lower

(d) Both loudness and pitch will remain unaffected

Sol. (d) 

Q.3 In SONAR, we use

(a) Ultrasonic waves

(b) Infrasonic waves

(c) Radio waves

(d) Audible sound waves

Sol. (a) 

Q.4 Sound travels in air if

(a) Particles of medium travel from one place to another

(b) There is no moisture in the atmosphere

(c) Disturbance moves

(d) Both particles as well as disturbance travel from one place to another.

Sol. (c) 

Q.5 When we change feeble sound to loud sound we increase its

(a) Frequency

(b) Amplitude

(c) Velocity

(d) Wavelength

Sol. (b) 

Q.6 In the curve (Figure) half the wavelength is

(a) A B

(b) B D

(c) D E

(d) A E

Sol. (d) 

Q.7 Earthquake produces which kind of sound before the main shock wave begins

(a) Ultrasound

(b) Infra sound

(c) Audible sound

(d) None of the above

Sol. (b) 

Q.8 Infra sound can be heard by

(a) Cow

(b) Bat

(c) Rhinoceros

(d) Human beings

Sol. (c) 

Q.9 Before playing the orchestra in a musical concert, a sit artist tries to adjust the tension and pluck the string suitably. By doing so, he is adjusting

(a) Intensity of sound only

(b) Amplitude of sound only

(c) Frequency of the sitar string with the frequency of other musical instruments

(d) Loudness of sound

Sol. (c)