waves Flashcards
Define the principle of superposition
When two or more waves meet at a point, the resultant displacement is the sum of the displacement of the individual waves.
Define Polarisation
When oscillations are in a single direction, which is perpendicular to the oscillation of the propagation.
For a progressive wave, what is meant by the frequency.
The number of oscillations per unit time of a point in a wave.
Direction of a transverse wave.
Perpendicular
Direction of a longitudinal wave
Parallel
An electromagnetic wave in free space has a frequency of 2.5 x 10^14 Hz.
Which region of the electromagnetic spectrum induces this frequency?
A- infrared
B- microwave
C- ultraviolet
D- x-ray
A- infrared
Which list of regions of the electromagnetic spectrum is in order of increasing wavelength from left to right?
A- gamma-ray —> ultraviolet —> infrared
B- infrared —> microwave —> ultraviolet
C- microwave —> x-ray —> infrared
D- x-ray —> ultraviolet —> gamma-ray
A- gamma-ray —> ultraviolet —> infrared
The principle of superposition states that a certain quantity is added when two or more waves meet at a point.
What is this quantity?
Displacement
In a two sources interference experiment, light of a single frequency is incident on a double slit.
The light waves emerging from the slits are coherent.
What is meant by coherent?
A- the waves are in phase.
B- the waves have a constant phase difference
C- the waves have the same amplitude
D- the waves interfere constructively wherever they overlap.
B- the waves have a constant phase difference.
A telescope detects and analyses some electromagnetic radiation of wavelength 2 cm.
Which type of telescope is it?
A- microwave telescope
B- optical telescope
C- radio telescope
D- x-ray telescope
A- microwave telescope
A beam of visible light is in a vacuum.
What could be the frequency of the light?
A- 5.0 x 10^5 Hz
B- 5.0 x 10^8 Hz
C- 5.0 x 10^11 Hz
D- 5.0 x 10^14 Hz
D- 5.0 x 10^14 Hz
Some sources of electromagnetic waves in free space are listed.
1- a radio wave transmitter
2- a source of x-rays
3- a 30 mm wavelength radar transmitter
4- a light-emitting diode that emits red light.
Which list gives the source in order of increasing wavelength, from left to right, of the waves emitted by the sources?
A- 1 -> 3 -> 4 -> 2
B- 2 -> 4 -> 1 -> 3
C- 2 -> 4 -> 3 -> 1
D- 3 -> 1 -> 4 -> 2
C- 2 -> 4 -> 3 -> 1
For a progressive wave, state what is meant by wavelength.
The minimum distance between two adjacent wavefronts.
For a progressive wave, state what is mean by its period.
The time taken for one complete oscillation of a point in a wave.
An electromagnetic wave in a vacuum has a wavelength of 8.4 x 10^-6 m.
State the name of the principal region of the electromagnetic spectrum for the wave.
Infrared
Which particle is a fundamental particle?
A- alpha-particle
B- electron
C- neutron
D- proton
B- electron
