Advertisements
Advertisements
प्रश्न
Answer briefly.
Explain what is meant by phase of a wave.
Advertisements
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.
APPEARS IN
संबंधित प्रश्न
Answer briefly.
Wave motion is doubly periodic. Explain.
Answer briefly.
Define amplitude.
Answer briefly.
Draw a wave and indicate points which are
- in phase
- out of phase
- have a phase difference of `pi/2`
Define the relation between velocity, wavelength, and frequency of the wave.
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
- the frequency
- the period
Sound wave A has period 0.015 s, sound wave B has a period of 0.025 s. Which sound has greater frequency?
Two sinusoidal plane waves of the same frequency having intensities I0 and 4I0 are travelling in the same direction. The resultant intensity at a point at which waves meet with a phase difference of zero radians is ______
The ratio of minimum to maximum wavelength in Balmer series is ____________.
Sound waves are passing through two routes one in straight path and the other along a semicircular path of radius r and are again combined into one pipe and superposed as shown in the figure. If the velocity of sound waves in the pipe is v, then frequencies of resultant waves of maximum amplitude will be integral multiples of ______.
In frequency modulated wave ______.
The frequency of a tuning fork is 384 per second and velocity of sound in air is 352 m/s. How far the sound has traversed while fork completes 48 vibration?
The following figure shows the shape of part of a long string in which transverse waves are produced by attaching one end of the slring to tuning fork of frequency 300 Hz. The velocity of the waves is ____________.
If velocity of sound in a gas is 360 m/s and the distance between a compression and the nearest rarefaction is 2 m, then the frequency of sound is ____________.
In a closed pipe, the note of fundamental frequency can be produced if the length of the air column is equal to ____________.
The frequency of a tuning fork is 220 Hz and the velocity of sound in air is 330 m/s. When the tuning fork completes 80 vibrations, the distance travelled by the ______.
A progressive wave of frequency 50 Hz is travelling with velocity 350 m/s through a medium. The change in phase at a given time interval of 0.01 s is ______.
The wavelength of two waves are 50 and 51 cm respectively. If the temperature of the room is 20°C then what will be the number of beats produced per second by these waves, when the speed of sound at 0°C is 332 m/s?
An astronaut is approaching the moon. He sends out a radio signal of frequency 5000 MHz and the frequency of echo is different from that of the original frequency by 100 kHz. His velocity of approach wrt, to the moon, 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?
Wave of frequency 500 Hz has a phase velocity 360 ms-1. The phase difference between two displacement at a certain point at time 10-3 s apart will be ______.
If a string fixed at both ends vibrates in four loops. The wavelength is 10 cm. The length of string is ______.
The energy of photon corresponding to a radiation of wavelength 600 nm is 3.32 × 10−19 J. The energy of a photon corresponding to a wavelength of 400 nm is ______.
