Advertisements
Advertisements
Question
A bucket kept under a running tap is getting filled with water. A person sitting at a distance is able to get an idea when the bucket is about to be filled.
(i) What change takes place in the sound to give this idea?
(ii) What causes the change in the sound?
Advertisements
Solution
(i) As the bucket is filled the sound gradually increases.
(ii) Frequency ∝ 1/length; Resonance takes place.
RELATED QUESTIONS
Define the Resonance phenomenon?
Give one example to illustrate forced vibrations.
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.
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).
Differentiate between the following:
Radio waves and light waves.
On keeping the stem of a vibrating tuning fork on the surface of a table, a loud sound is heard. Give reason.
Explain why stringed musical instruments, like the guitar, are provided with a hollow box.
Explain a person walking past a railway line, in the middle of night hears a ringing sound along with the sound of his footsteps.
Explain Why are stringed musical instruments provided with large sound boxes?
