Question

Which of the following statements are correct?
i. Sound is produced by vibrations.
ii. Sound requires a medium for propagation.
iii. The audible range of sound for humans is 10 Hz - 10 kHz.

• A.
  i, ii, and iii
• B.
  i and iii only
• C.
  i and ii only
• D.
  ii and iii only

Answer 1

The correct option is C

i and ii only
Out of the given statements only (i) and (ii) are correct because:

• Sound is produced by vibrations. For example, in a guitar, the sound is produced by the vibration of strings.
• Sound requires a medium for its propagation. The medium can be solid, liquid or gas.

Statements (iii) is incorrect because humans can detect sounds in a frequency range of about 20 Hz to 20 kHz.