Sound
NCERT Exemplar Problems
Multiple Choice Questions
Question 1: Note is a sound
- of mixture of several frequencies
- of mixture of two frequencies only
- of a single frequency
- always unpleasant to listen
Answer: (a) of mixture of several frequencies
Question 2: A key of a mechanical piano struck gently and then struck again but much harder this time. In the second case
- sound will be louder but pitch will not be different
- sound will be louder and pitch will also be higher
- sound will be louder but pitch will be lower
- both loudness and pitch will remain unaffected
Answer: (d) both loudness and pitch will remain unaffected
Question 3: In SONAR, we use
- ultrasonic waves
- infrasonic waves
- radio waves
- audible sound waves
Answer: (a) Ultrasonic waves
Question 4: Sound travels in air if
- particles of medium travel from one place to another
- there is no moisture in the atmosphere
- disturbance moves
- both particles as well as disturbance travel from one place to another.
Answer: (c) Disturbance moves
Question 5: When we change feeble sound to loud sound we increase its
- Frequency
- Amplitude
- Velocity
- Wavelength
Answer: (b) Amplitude
Question 6: In the curve (Figure) half the wavelength is
- A B
- B D
- D E
- A E
Answer: (a) AB
Question 7: Earthquake produces which kind of sound before the main shock wave begins
- Ultrasound
- Infrasound
- audible sound
- none of the above
Answer: (b) Infrasound
Question 8: Infrasound can be heard by
- Dog
- Bat
- Rhinoceros
- Human beings
Answer: (c) Rhinoceros
Question 9: Before playing the orchestra in a musical concert, a sitarist tries to adjust the tension and pluck the string suitably. By doing so, he is adjusting
- intensity of sound only
- amplitude of sound only
- frequency of the sitar string with the frequency of other musical instruments
- loudness of sound
Answer: (c) Frequency of the sitar string with the frequency of other musical instruments