An open organ pipe of length l is sounded together with another open organ pipe of length l + x in their fundamental tones. Speed of sound in air is v, the beat frequency heard will be (`x lt lt l`)

Options

A. `(vx)/(4l^(2))`
B. `(vl^(2))/(2x)`
C. `(vx)/(2l^(2))`
D. `(vx^(2))/(2l)`

Answer

C