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प्रश्न
What are the factors that affect the frequency of a vibrating string and how do they affect the frequency?
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उत्तर
The frequency (f) of a vibrating string is affected by:
(i) The length of the vibrating string. Frequency is inversely proportional to the length, i.e, `"f"α1/"l"`. it means, if length increases, frequency becomes less and if length decreases, frequency increases.
(ii) It is directly proportional to the square root of the tension, other factors remaining the same, e.g., if tension (or stretching force) is made 4 times, then the frequency will be `(sqrt4=2)` doubled.
(iii) The frequency, (f) is inversely proportional to the square root of the mass of unit length of the vibrating string, i.e., `"f"α1/sqrt"m′"` if m' is the mass of unit length of the string. Since m' = πr2.l, it shows that f is `α1/sqrt("r"^2)` or `1/"r"`, where r is the radius of the vibrating strings.
संबंधित प्रश्न
In the diagram below, A, B, C, D are four pendulums suspended from the same elastic string PQ. The length 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
1) Name the type of vibrations taking place in pendulums B and D?
2) What is the state of pendulum C?
3) State the reason for the type of vibrations in pendulum B and C.
What are mechanical waves?
Resonance is a special case of ______ vibrations, when frequency of the driving force is ______ natural frequency of the body.
When a body vibrates under a periodic force, the vibrations of the body are ______.
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 ?
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).
Give two examples of forced vibrations.
Explain a person walking past a railway line, in the middle of night hears a ringing sound along with the sound of his footsteps.
What do you understand by free (or natural) vibrations?
