A vehicle, with a horn of frequency n, is moving with a velocity of 30 m/s in a direction perpendicular to the straight line joining the observer and the vehicle. The observer perceives the sound to have a frequency n + n₁ . Then, n₁ is equal to: (take velocity of sound in air as 330 m/s):

• A

  ${\mathrm{n}}_1=10\mathrm{n}$

• B

  $n_1=-n$

• C

  ${\mathrm{n}}_1=0.1\mathrm{n}$

• D

  $n_1=0$