Available Answers

1. 1.

   Look at these pictures. Identify which objects will produce a clear and soothing sound? In which case will you call it a noise?

   

2. 2.

   Fill in the blanks.

   1. Sound is produced due to _______________.
   2. Sound requires _______________ to travel.
   3. The sound in humans is produced in the _______________.
   4. The number of oscillation per second is called _______________.
   5. The _______________ collects the sound waves and directs them to the ear tube.
3. 3.

   Tick (√) the correct option.

   1. Which of the following is the unit of frequency?
      1. Metre
      2. Per metre
      3. Second
      4. Per second
   2. Rapid back and forth movement of a body about its mean position is called
      1. time period
      2. frequency
      3. amplitude
      4. vibration
   3. Which of the following depends on the amplitude of the vibrations?
      1. Pitch
      2. Quality
      3. Loudness
      4. None of the above
   4. Sound of which frequency can be heard by the human ear
      1. 60 Hz
      2. 600 Hz
      3. 25000 Hz
      4. all of above
   5. Vibration with high frequency will have a
      1. low pitch
      2. high pitch
      3. soft voice
      4. loud voice
4. 4.

   Give one word for the following.

   1. The sound waves with a frequency below 20 Hz
   2. The maximum displacement from the mean position during an oscillation
   3. Unpleasant, discomfort-causing sound from any source
   4. Time taken to complete one oscillations
   5. Musical instruments which produce sound by a vibrating air column
5. 5.

   Match the columns.

   COLUMN A	COLUMN B
   1. Pitch	a. Wind instrument
   2. Trumpet	b. Stringed instrument
   3. Guitar	c. Amplitude
   4. Loudness	d. Noise pollution
   5. Blaring loudspeakers	e. Frequency

    

6. 6.

   How are sound waves produced?