$A$ hollow pipe of length $0.8 \ m$ is closed at one end. At its open end,a $0.8 \ m$ long uniform string is vibrating in its second harmonic and it resonates with the fundamental frequency of the pipe. If the tension in the string is $50 \ N$ and the speed of sound in air is $320 \ m/s$,the mass of the string is: (in $g$)

Four different independent waves are represented by $(i)$ $y_1 = a_1 \sin \omega t$,$(ii)$ $y_2 = a_2 \sin 2\omega t$,$(iii)$ $y_3 = a_3 \cos \omega t$,and $(iv)$ $y_4 = a_4 \sin (\omega t + \frac{\pi}{3})$. With which two waves is interference possible?

$A$ transverse sinusoidal wave of amplitude $a,$ wavelength $\lambda,$ and frequency $n$ is travelling on a stretched string. The maximum speed of any point on the string is $v/10,$ where $v$ is the speed of propagation of the wave. If $a = 10^{-3} \ m$ and $v = 10 \ m/s,$ then $\lambda$ and $n$ are given by:

$A$ composite string is made up by joining two strings of different masses per unit length $\mu$ and $4\mu$. The composite string is under the same tension. $A$ transverse wave pulse $Y = (6 \text{ mm}) \sin(5t + 40x)$,where $t$ is in seconds and $x$ in meters,is sent along the lighter string towards the joint. The percentage of power transmitted to the heavier string through the joint is approximately ..... $\%$

Following are expressions for four plane simple harmonic waves:
$(i) \, y_1 = A \cos 2\pi \left( n_1 t + \frac{x}{\lambda_1} \right)$
$(ii) \, y_2 = A \cos 2\pi \left( n_1 t + \frac{x}{\lambda_1} + \frac{1}{2} \right)$
$(iii) \, y_3 = A \cos 2\pi \left( n_2 t + \frac{x}{\lambda_2} \right)$
$(iv) \, y_4 = A \cos 2\pi \left( n_2 t - \frac{x}{\lambda_2} \right)$
The pairs of waves which will produce destructive interference and stationary waves respectively in a medium are:

The wavelength of light in the visible part $(\lambda_V)$ and for sound $(\lambda_S)$ are related as: