What is phase difference between two waves if the resultant amplitude due to their superposition is same as that of the waves? 

In Melde's experiment, in parallel position when mass $m_1$ is kept in the pan, then the number of loops obtained is $p_1$ and when mass $m_2$ is kept the number of loops is $p_2$; then the mass of pan $m_0$is

A pipe of:length $85 \mathrm{cm}$is closed from one end. Find the number of possible natural oscillations of air column in the pipe whose frequencies lie below $1250 \mathrm{Hz}$. The velocity of sound in air is $340 \mathrm{m} {\mathrm{s}}^{-1}$.

The closed and open organ pipes have same length. When they are vibrating simultaneously in first overtone, produce three beats. The length of open pipe is made $\frac{1}{3}$ and closed pipe is made three times the original, the number of beats produced will be 

A sonometer wire of length $1.5 \mathrm{m}$ is made of steel. The tension in it produces an elastic strain of $1 \% .$ What is the fundamental frequency of steel if density and elasticity of steel are $7.7\times {10}^3\mathrm{kg} {\mathrm{m}}^{-3}$ and $2.2\times {10}^{11}\mathrm{N} {\mathrm{m}}^{-2}$ respectively?

Assertion: If two tuning forks are sounded together, they produce $5 \mathrm{beats} {\mathrm{s}}^{-1}$. If by putting Wax on one tuning fork, beat frequency increases to$6 \mathrm{beats} {\mathrm{s}}^{-1}$ , then one can conclude that wax is put on tuning fork with lesser frequency.

Reason: By putting wax on a tuning fork, one can decrease its frequency.

An open pipe of length $L$ vibrates in its fundamental mode. The pressure variation is maximum

In an organ pipe whose one end is at $x=0$, the pressure is expressed by $P=P_{0} \cos \frac{3 \pi x}{2} \sin 300 \pi t$ where $x$ is in metre and $t$ in seconds. The organ pipe can be

Four open organ pipes of different lengths and different gases at same temperature are as shown in figure. Let $F_{\mathrm{A}},F_{\mathrm{B}},F_{\mathrm{C}}$ and $F_{\mathrm{D}}$ be their fundamental frequencies; then $Take\left[{\gamma }_{C{O}_2}={\gamma }_{H_2}={\gamma }_{O_2}={\gamma }_{N_2}=\frac{7}{5}\right]$