An aluminium rod of length 90 cm is clamped at its midpoint and is set into longitudinal vibrations by stroking it with resined cloth. Assume that the rod vibrates in its fundamental mode of vibration . The density of aluminium is 2600 kg/`m^(3)` and its Young's modulus is `7.80 xx 10^(10) N//m^(2)`. speed of sound in air is 340 m/s.
The wavelength of sound produced in the rod is :

Options

A. 80 cm
B. 120 cm
C. 100 cm
D. 180 cm

Answer

D

Explanation

`(lambda)/(2) = l rArr lambda = 2l = 2 xx 90 = 180 ` cm
so correct choice is (d).