$A$ standing wave with a number of loops is produced on a string fixed at both ends. Which one of the following statements is correct?

If you set up the seventh harmonic on a string fixed at both ends,how many nodes and antinodes are set up in it?

$A$ string of length $0.5 \text{ m}$ and mass $10^{-3} \text{ kg}$ is tightly clamped at its ends. The tension in the string is $0.8 \text{ N}$. Identical wave pulses are produced at one end at equal intervals of time $\Delta t$. What is the minimum value of $\Delta t$ which allows constructive interference between successive pulses (in $\text{ s}$)?

Stationary waves are produced in a $10\,m$ long stretched string. If the string vibrates in $5$ segments and the wave velocity is $20\,m/s$,the frequency is ..... $Hz$.

For the stationary wave $y = 4 \sin \left(\frac{\pi x}{15}\right) \cos (96 \pi t)$,the distance between a node and the next antinode is

When a wave propagating on a string gets reflected from a fixed rigid support,what is the change in its phase?