Which is the most important property of a stationary wave?

$Assertion :$ For the formation of stationary waves,the medium must be bounded having definite boundaries.
$Reason :$ In the stationary wave,some particles of the medium remain permanently at rest.

$A$ stationary wave is formed with $3$ nodes along the length of a string of $90 \ cm$. The wavelength of the wave is: (in $cm$)

The distance between the successive node and anti-node is

$A$ string fixed at both its ends vibrates in $5$ loops as shown in the figure. The total number of nodes and antinodes are respectively:

The transverse displacement of a string (clamped at its both ends) is given by $y(x,t) = 0.06 \sin(2\pi x / 3) \cos(120\pi t)$. All the points on the string between two consecutive nodes vibrate with