Waves, light and sound Flashcards
Wave equation 1
v = f x λ
v is the speed of wave in m/s
f is the frequency in Hz
λ is the wavelength in meters
Wave equation 2
f = 1 / T
T is the time period of wave in
seconds
Movement of the particles
of the medium
Longitudinal waves=> back and forth in the direction of the
waves
Transverse waves=> perpendicular to the direction of the waves
Law of reflection
Angle of incidence i = angle of reflection
angle i = angle r
Refraction
From lighter to denser medium → light bend towards the normal
From denser to lighter medium →light bend away from the
normal
Refractive index n
n = sin∠ i / sin∠r
*Refractive index has no unit
Refractive index n
n = speed of light in air or vacuum / speed of light in any other medium
Image from a plane mirror
Virtual, upright, same size and laterally inverted,
same distance from the mirror inside
Image from a convex lens
When close: virtual, enlarge, upright
When far: real, small, upside down
Image from a concave lens
Virtual, upright, small
Image from a concave lens
Virtual, upright, small
Critical angle
When light goes from denser to lighter medium, the incident
angle at which the reflected angle is 90 o
,is called critical angle
Total internal
reflection (TIR)
When light goes from denser to lighter medium, the refracted ray
bend inside the same medium then this is called (TIR)
Electromagnetic spectrum
In order of increasing frequency: Radio waves Micro waves Infra red Visible light Ultraviolet X-rays Gamma rays
Colours of visible
spectrum (light)
R- red O- orange Y- yellow G- green B- blue I- indigo V- violet
