Statement(A): The reflection of sound from an extended object is echo
Statement(B): The super position of waves of same frequency is beats
Statement(C): The apparent change in frequency of source of sound due to relative motion between source and observer is Doppler effect
Statement(D): The super position of wave of slightly differ in frequency is stationary waves

Options

A. Both 'A' and 'R' are true and 'R' is the correct, explanation of 'A'.
B. Both 'A' and 'R' are true and 'R' is not the correct explanation of 'A'
C. A' is true and 'R' is false
D. Both 'A' and 'R' are false

Answer

A