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प्रश्न
Answer briefly.
Explain what is meant by phase of a wave.
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उत्तर
- The state of the oscillation of a particle is called the phase of the particle.
- The displacement, direction of velocity, and oscillation number of the particle describe the phase of the particle at a place.
Displacement as a function of distance along the wave - Particles r and t (q and u or v and s) have the same displacements but the directions of their velocities are opposite.
- Particles having same magnitude of displacements and the same direction of velocity are said to be in phase during their respective oscillations. Example: particles v and p.
- Separation between two particles which are in phase is wavelength (λ).
- The two successive particles differ by ‘1’ in their oscillation number i.e., if particle v is at its nth oscillation, particle p will be at its (n +1)th oscillation as the wave is travelling along + X direction.
- In the given graph, if the disturbance (energy) has just reached the particle w, the phase angle corresponding to particle is 0°. At this instant, particle v has completed quarter oscillation and reached its positive maximum (sin θ = +1). The phase angle θ of this particle v is `pi^"c"/2` = 90° at this instant.
- Phase angles of particles u and q are π c (180°) and 2πc (360°) respectively.
- Particle p has completed one oscillation and is at its positive maximum during its second oscillation.
∴ phase angle = 2πc + `pi^"c"/2 = (5pi^"c")/2`. - v and p are the successive particles in the same state (same displacement and the same direction of velocity) during their respective oscillations. Phase angle between these two differs by 2πc.
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संबंधित प्रश्न
Answer briefly.
Define amplitude.
Answer briefly.
Define wavelength of a wave.
Answer briefly.
Draw a wave and indicate points which are
- in phase
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Define progressive wave.
State any four properties of progressive wave.
Solve the following problem.
A certain sound wave in air has a speed 340 m/s and wavelength 1.7 m for this wave, calculate
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Solve the following problem.
A tuning fork of frequency 170 Hz produces sound waves of wavelength 2 m. Calculate the speed of sound.
Sound wave A has period 0.015 s, sound wave B has a period of 0.025 s. Which sound has greater frequency?
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In frequency modulated wave ______.
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(Take, the speed of sound in air = 340 m/s)
Two instruments having stretched strings are being played in unison. When the tension of one of the instruments is increased by 1%, 3 beats are produced in 2 s. The initial frequency of vibration of each wire is ______.
A progressive wave of frequency 500 Hz is travelling with a velocity of 360 m/s. How far apart are two points 60° out of phase?
If a string fixed at both ends vibrates in four loops. The wavelength is 10 cm. The length of string is ______.
