$A$ wave is reflected from a rigid support. The change in phase on reflection will be

Find the wrong statement from the following about the equation of a stationary wave given by $Y = 0.04 \cos(\pi x) \sin(50 \pi t) \text{ m}$,where $t$ is in seconds.

The equation $\overrightarrow{\phi}(x, t) = \overrightarrow{j} \sin \left( \frac{2\pi}{\lambda} vt \right) \cos \left( \frac{2\pi}{\lambda} x \right)$ represents:

Stationary waves are set up in an air column. The velocity of sound in air is $330 \ m/s$ and the frequency is $165 \ Hz$. The distance between the nodes is ... $m$.

The correct statement about stationary waves is that

$A$ string fixed at both ends vibrates in a resonant mode with a separation of $2.0 \, cm$ between consecutive nodes. For the next higher resonant frequency,this separation is reduced to $1.6 \, cm$. The length of the string is .... $cm$.