Summary of Light in Physics
1. Nature of Light
W
● ave-Particle Duality:Light exhibits both wave-likeand particle-like properties.
● Speed of Light:In a vacuum, the speed of light cccis approximately 3×1083 \times
10^83×108 m/s.
2. Properties of Light Waves
W
● avelength (λ\lambdaλ):Distance between successivecrests.
● Frequency (fff):Number of cycles per second, relatedto wavelength by the equation
c=λfc = \lambda fc=λf.
● Amplitude:Height of the wave, related to the intensityof light.
3. Reflection
L
● aw of Reflection:The angle of incidence equals theangle of reflection.
● Types of Reflection:
○ Regular Reflection:Smooth surfaces (e.g., mirrors).
○ Diffused Reflection:Rough surfaces scatter light.
4. Refraction
B
● ending of Light:Occurs when light passes from onemedium to another.
● Snell's Law:n1sin(θ1)=n2sin(θ2)n_1 \sin(\theta_1)= n_2
\sin(\theta_2)n1sin(θ1)=n2sin(θ2), where nnn is the refractive index.
● Total Internal Reflection:Occurs when light movesfrom a denser to a rarer medium
and the angle of incidence exceeds the critical angle.
5. Lenses
C
● onvex Lens:Converging lens; focuses parallel raysto a point.
● Concave Lens:Diverging lens; spreads parallel raysapart.
● Lens Formula:1f=1v−1u\frac{1}{f} = \frac{1}{v} -\frac{1}{u}f1=v1−u1
○ fff: Focal length
○ vvv: Image distance
○ uuu: Object distance
6. Optical Instruments
M
● icroscope:Uses lenses to magnify small objects.
● Telescope:Combines lenses or mirrors to observe distantobjects.
● Camera:Captures images using a lens and a light-sensitivesurface.
1. Nature of Light
W
● ave-Particle Duality:Light exhibits both wave-likeand particle-like properties.
● Speed of Light:In a vacuum, the speed of light cccis approximately 3×1083 \times
10^83×108 m/s.
2. Properties of Light Waves
W
● avelength (λ\lambdaλ):Distance between successivecrests.
● Frequency (fff):Number of cycles per second, relatedto wavelength by the equation
c=λfc = \lambda fc=λf.
● Amplitude:Height of the wave, related to the intensityof light.
3. Reflection
L
● aw of Reflection:The angle of incidence equals theangle of reflection.
● Types of Reflection:
○ Regular Reflection:Smooth surfaces (e.g., mirrors).
○ Diffused Reflection:Rough surfaces scatter light.
4. Refraction
B
● ending of Light:Occurs when light passes from onemedium to another.
● Snell's Law:n1sin(θ1)=n2sin(θ2)n_1 \sin(\theta_1)= n_2
\sin(\theta_2)n1sin(θ1)=n2sin(θ2), where nnn is the refractive index.
● Total Internal Reflection:Occurs when light movesfrom a denser to a rarer medium
and the angle of incidence exceeds the critical angle.
5. Lenses
C
● onvex Lens:Converging lens; focuses parallel raysto a point.
● Concave Lens:Diverging lens; spreads parallel raysapart.
● Lens Formula:1f=1v−1u\frac{1}{f} = \frac{1}{v} -\frac{1}{u}f1=v1−u1
○ fff: Focal length
○ vvv: Image distance
○ uuu: Object distance
6. Optical Instruments
M
● icroscope:Uses lenses to magnify small objects.
● Telescope:Combines lenses or mirrors to observe distantobjects.
● Camera:Captures images using a lens and a light-sensitivesurface.
