Advertisements
Advertisements
प्रश्न
In following figure shows A, B , C and D represent test tube each of height 20 cm which are filled with water up to heights of 12 cm, 14 cm, 16cm and 18cm respectively. If a vibrating tuning fork is placed over the mouth if test tube D, a loud sound is heard.
- Describe the observations with the tubes A, B and C when the vibrating tuning fork is placed over the mouth of these tubes.
- Give the reason for your observation in each case.
- State the principle illustrated by the above experiment.
Advertisements
उत्तर
- No loud sound is heard with the tubes A and C, but a loud sound is heard with the tube B.
- While tubes A and C do not experience resonance with their air columns, tube B does. The air column length in tube D is 20 – 18 = 2 cm, while in tube B it is 20 – 14 = 6 cm, which is three times the length in tube D. Consequently, the frequency of vibrations in both tubes is identical. Contrarily, air column vibrations in tubes A and C do not have the same frequency as those in tube B.
- Resonance happens when the air column vibration frequency is exactly the same as the tuning fork vibration frequency.
APPEARS IN
संबंधित प्रश्न
In following figure shows two tuning forks A and B of the same frequency mounted on two separate sound boxes with their open ends facing each other. The fork A is set into vibration.
- Describe your observation.
- State the principle illustrated by this experiment.
In following figure shows A, B, C and D are four pendulums suspended from the same elastic string XY. Lengths of pendulum A and D are equal, while the length of pendulum B is smaller and the pendulum C is longer. The pendulum A is set into vibration.
(a) what is your observation? (b) Give reason for your observation.
Why are the stringed instruments like guitar provided with a hollow sound box?
A tuning fork of frequency 256 Hz will resonate with another tuning fork of frequency:
(i) Define resonant vibrations.
(ii) Which characteristic of sound, makes it possible to recognize a person by his voice without seeing him?
In Fig. A, B, C and D are four pendulums suspended from the same elastic string XY. The lengths of pendulum A and D are equal, while the length of pendulum B is shorter and of the pendulum C is longer. Pendulum A is set into vibrations.
- What is your observation about the vibrations of pendulum D?
- Give reason for your observation in part (a).
- What type of vibrations take place in pendulums Band C?
- Give reason for the answer in part (c).
The diagram below shows three different modes of vibration P, Q and R of the same string of a given length.
 |
 |
 |
| P | Q | R |
- Which vibration will produce a louder sound and why?
- Which vibration will produce sound of maximum shrillness (or pitch) and why?
- What is the ratio of wavelength of vibrations P and R?
What do you mean by resonance? When does resonance occur?
The rearview mirror of a motorbike starts vibrating violently at some particular speed of the motorbike. What is the name of the phenomenon taking place? Why does the happen?
What do you understand by free vibrations of a body? Draw a displacement-time graph to represent them. Given one example.
