Statement I: The apparent freqeuncy which is the frequency as noted by an observer or an observing detection device of the acoustic wave that moves from the source to the observer propagating in a medium may be different from its true frequency.
Statement II: A source in motion relative to an observer sends out less or more number of waves per metre distance in the medium and an observer in motion collects less or more number of waves per second that when both of them remain at rest relatively.

Options

A. Statement I is true, Statement II is true: Statement II is a correct explanation for statement I.
B. Statement I is true, Statement II is true, Statement II is NOT a correct explanation for Statement I.
C. Statement I is true, Statement II is false
D. Statement I is falce: Statement II is true

Answer

C

Explanation

Both statements are true. The wavelength of a wave from a source moving towards or away from an observer changes due to the motion of the source. Similarly, for an observer moving towards or away from a source, it is the freqeuncy (number of waves passing him per second) that is affected by his motion.