NCERT Solutions for Chapter: Waves, Exercise 4: SA

The wave pattern on a stretched string is shown in Figure. Interpret what kind of wave this is and find its wavelength.

The pattern of standing waves formed on a stretched string at two instants of time is shown in Figure. The velocity of two waves super-imposing to form stationary waves is $360 {\mathrm{ms}}^{-1}$ and their frequencies are $256 \mathrm{Hz}$.

(a) Calculate the time at which the second curve is plotted.

The pattern of standing waves formed on a stretched string at two instants of time are shown in Figure. The velocity of two waves super-imposing to form stationary waves is $360 {\mathrm{ms}}^{-1}$ and their frequencies are $256 \mathrm{Hz}$.

(b) Mark nodes and antinodes on the curve.

The pattern of standing waves formed on a stretched string at two instants of time are shown in Fig. The velocity of two waves superimposing to form stationary waves is $360 \text{m/s}$ and their frequency is $256 \text{Hz}$.

Calculate the distance between A' and C'.

A tuning fork vibrating with a frequency of $512 \mathrm{Hz}$ is kept close to the open end of
a tube filled with water (Figure). The water level in the tube is gradually lowered. When the water level is $17 \text{cm}$ below the open end, the maximum intensity of sound is heard. If the room temperature is $20°\mathrm{C}$, calculate

(a) speed of sound in air at room temperature

A tuning fork vibrating with a frequency of $512 \mathrm{Hz}$ is kept close to the open end of a tube filled with water. The water level in the tube is gradually lowered. When the water level is $17 \mathrm{cm}$ below the open end, the maximum intensity of sound is heard. If the room temperature is $20°\mathrm{C}$, calculate

(b) speed of sound in air at $0°\mathrm{C}$

A tuning fork vibrating with a frequency of $512 \mathrm{Hz}$ is kept close to the open end of a tube filled with water. The water level in the tube is gradually lowered. When the water level is $17 \mathrm{cm}$ below the open end, the maximum intensity of sound is heard. If the room temperature is $20°\mathrm{C},$ calculate

(c) if the water in the tube is replaced with mercury, will there be any difference in your observations?

Show that when a string fixed at its two ends vibrates in $1$ loop, $2$ loops, $3$ loops and $4$ loops, the frequencies are in the ratio $1: 2: 3: 4$