Summary Notes - Topic 3 CAIE Physics IGCSE Flashcards
What is the definition of amplitude in wave properties?
The distance from the equilibrium position to the maximum displacement
Amplitude is a key characteristic that affects the energy of the wave.
What is wavelength in the context of waves?
The distance between a point on one wave and the same point on the next wave
Wavelength is crucial for determining the frequency and speed of the wave.
Define frequency in wave properties.
The number of waves that pass a single point per second
Frequency is measured in hertz (Hz).
How is wave speed calculated?
Speed = Frequency × Wavelength
This relationship shows how wave speed is dependent on frequency and wavelength.
What are transverse waves?
Waves with peaks and troughs where vibrations are at right angles to the direction of travel
An example of transverse waves is light.
What are longitudinal waves?
Waves consisting of compressions and rarefactions where vibrations are in the same direction as the direction of travel
An example of longitudinal waves is sound.
What is a wavefront?
A surface containing points affected in the same way by a wave at a given time
Examples include crests or troughs of waves.
What is the law of reflection?
Angle of incidence = Angle of reflection
This law applies to all reflective surfaces.
What happens to waves during refraction?
The speed of a wave changes when it enters a new medium
The frequency stays the same, but the wavelength changes.
What is diffraction?
Waves spread out when they go around the sides of an obstacle or through a gap
The amount of diffraction increases with a narrower gap or greater wavelength.
What is the relationship between wavelength and diffraction?
The narrower the gap or the greater the wavelength, the more the diffraction
This is crucial for understanding wave behavior in various scenarios.
How does light reflect off surfaces?
Light rays bounce off a surface and change direction while staying in the same medium
The angle of incidence equals the angle of reflection.
What characterizes an optical image formed by a plane mirror?
Same size as the object, same distance behind the mirror, virtual, laterally inverted
This describes how images are perceived in plane mirrors.
What is the refractive index?
The ratio between the speed of light in a vacuum and the speed of light in the medium
It is a dimensionless number indicating how much light slows down in a medium.
What is total internal reflection?
Occurs when the angle of incidence is greater than the critical angle, reflecting light back into the medium
This phenomenon is essential for the functioning of optical fibers.
What are converging lenses used for?
To bring light rays together at a point called the principal focus
Examples include magnifying glasses and binoculars.
What happens during the dispersion of light through a prism?
White light splits into its constituent colours due to different speeds in the glass
The order of colours is red, orange, yellow, green, blue, indigo, violet (ROYGBIV).
What is the speed of electromagnetic waves in a vacuum?
3.0 x 10^8 m/s
This speed is approximately the same in air.
What are some uses of radio waves?
Used for radio and television communications
They have a long wavelength and are reflected by the ionosphere.
What is the difference between analogue and digital signals?
Analogue signals are continuously varying; digital signals consist of discrete binary values
Digital signals are preferred for modern communication due to efficiency.
How is the speed of sound measured?
By making a noise at a known distance from a solid wall and recording the echo time
Speed = distance/time, accounting for the round trip.
What is the range of audible frequencies for a healthy human ear?
20 Hz to 20,000 Hz
Frequencies above 20,000 Hz are classified as ultrasound.
What is sonar used for?
To detect flaws in materials, medical imaging, and measuring water depth
It utilizes ultrasound waves for these applications.
