Wave Motion Flashcards
What is wave motion?
It is the transfer of energy by propagation of oscillations without the net movement of the medium.
What is a wavefront?
It is a surface over which a wave is at the same phase of oscillation at all points.
What is displacement of a wave?
It is the distance and direction of the medium’s element from its equilibrium position.
What is the amplitude of a wave?
It is the maximum magnitude of the displacement.
What is the period of a wave?
It is the time taken for the medium to complete one oscillation cycle.
What is frequency of a wave?
It is the number of complete oscillations per unit time made by a point of the wave.
What is wavelength?
If is the distance between two consecutive points in the wave that are at the same phase of oscillation.
What is speed of a wave?
It is the distance travelled by any pet if a waveform per unit time.
What is the phase difference between two waves or between two points in a wave?
It is the difference in the phase of their oscillation cycle expressed in terms of an angle.
Distance/wavelength x 2π
What does it mean when two waves are coherent?
There is constant phase difference between them which implies they have the same frequency.
What is the difference between two coherent waves at a particular time?
If is the distance between the points of the waves that are in the same phase out of the wavelength x2π
When the phase difference is 0 or an integer multiple of 2π, they are _____.
In phase.
What is the difference between propagation and oscillation?
Propagation is wave motion whole oscillation refers to oscillation of the medium.
What is speed of wave?(not medium!) How is it derived?
v=fλ
v= distance/time = λ/T = fλ
What is the difference between progressive waves and stationary waves?
Progressive waves transfer energy as a result of oscillation while stationary waves …..
How are stationary waves formed?
By the superposition of 2 progressive waves.
What is wave intensity?
It is the average energy transferred per unit time per unit area perpendicular to the direction of wave propagation.
State the relationship between intensity and amplitude of a wave.
I is directly proportional to A^2.
What is the difference between transverse waves and longitudinal waves?
Transverse waves: medium oscillates in the plane normal to the direction of energy transfer or wave propagation
Longitudinal waves: medium oscillates in the direction parallel to the direction of energy transfer or wave propagation
What is polarisation of waves?
A waves oscillations are made to occur in one direction only, in the plane normal to the direction of energy transfer.
Why can’t longtitudinal waves be polarised?
They can only oscillate in the direction of energy transfer.
How is light polarised?
It is polarised when passed through a Polaroid.
When light passes through a Polaroid at and angle θ, what will its new amplitude be?
*angle to the amplitude.
Acosθ
How to determine whether light is polarised?
By viewing the light source through a piece of Polaroid. Unpolarised light will be visible at all angles.
Sound waves are ______ waves.
Longtitudinal
The cathode-Ray-oscilloscope represents _____ using _____.
Waveforms using time-base represented by length.
To obtain a wave form of sound, the c.r.o. is _____.
Connected to a microphone which is placed near the source. The time-base is adjusted until a stationary trace is obtained.
How to determine the wave length of sound using stationary waves?
Place the source of sound at a distance from a PLANE REFLECTING wall in a large chamber. Stationary waves are formed by incident and reflected sound waves.
A microphone connected to the cro is moved from one mode to another to determine the Nidal separation. λ is 2x the separation.
