Advertisements
Advertisements
प्रश्न
Explain a tuning fork (vibrating) is held close to ear. One hears a faint sound. The same vibrating tuning fork is placed on table, such that its handle is in contact with table, one hears a loud sound.
Advertisements
उत्तर
When the tuning fork is held close to ear, then small amount of air is disturbed and hence sound is faint. When the handle of the vibrating tuning fork is held aganist table, it makes the table top to vibrate, with forced vibrations. As the table top has a larger surface area, therefore large volume of air is set into vibrations, thereby producing a loud sound.
APPEARS IN
संबंधित प्रश्न
In the diagram below, A, B, C, D are four pendulums suspended from the same elastic string PQ. The lengths of A and C are equal to each other, while the length of pendulum B is smaller than that of D. Pendulum A is set into a mode of vibrations.
- Name the type of vibrations taking place in pendulums B and D.
- What is the state of pendulum C?
- State the reason for the type of vibrations in pendulums B and C.
Resonance is a special case of ______ vibrations, when frequency of the driving force is ______ natural frequency of the body.
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.
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.
Two pendulums C and D are suspended from a wire as shown in the figure give below. Pendulum C is made to oscullate by displaying it from its mean position. It is seen that D also starts oscillating.
(i) Name the type of oscillation, C will execute.
(ii) Name the type of oscillation, D will execute.
(iii) If the length of D is made equal to C then what difference will you notice in the oscillations of D ?
(iv) What is the name of the phenomenon when the length of D is made equal to C ?
On keeping the stem of a vibrating tuning fork on the surface of a table, a loud sound is heard. Give reason.
The rearview mirror of a motorbike starts vibrating violently at some particular speed of the motorbike, what could be done to stop the violent vibrations.
What do you understand by free (or natural) vibrations?
