A string 25 cm long having a mass of 2.5 g. is under tension. A pipe closed at one end is 40 cm long. When the string is set vibrating in its first overtone and the air in the pipe in its fundamental frequency, 8 beats/sec. are heard. It is observed that decreasing the tension in the string, decreases the beat frequency. If the speed of sound in air is 320 m/s , the tension in the string is

Options

A. 900 N
B. 275 N
C. 27.04 N
D. 176 N

Answer

C