1 | Wave equation 1 | v is the speed of wave in m/s f is the frequency in Hz λ is the wavelength in meters |
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2 | Wave equation 2 | T is the time period of wave in seconds |
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3 | 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 |
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4 | Law of reflection | ||
5 | Refraction | From lighter to denser medium → light bend towards the normal From denser to lighter medium →light bend away from the normal |
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6 | Refractive index n | Refractive index has no unit | |
7 | Refractive index n | ||
8 | Image from a plane mirror | Virtual, upright, same size and laterally inverted, same distance from the mirror inside |
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9 | Image from a convex lens | When close: virtual, enlarge, upright When far: real, small, upside down |
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10 | Image from a concave lens | Virtual, upright, small | |
11 | Critical angle | When light goes from denser to lighter medium, the incident angle at which the reflected angle is 9o, is called critical angle. |
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12 | 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) | |
13 | Electromagnetic Spectrum:→ this way the frequency decreases and wavelength increases Gamma rays ↔ X-rays ↔ UV ↔ Visible light ↔ IR ↔ Micro waves ↔ Radio waves |
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14 | Colours of visible spectrum (light) |
VIBGYOR (from bottom-up) | |
15 | Speed of light | ||
16 | Light wave | Electromagnetic waves | |
17 | Sound wave | longitudinal waves particle of the medium come close → compression particles of the medium far apart → rarefaction |
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18 | Echo | v is the speed of sound waves, d is the distance in meters between source and the reflection surface and t is the time for echo |
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19 | Properties of sound waves | Pitch means the frequency of the wave Loudness means the amplitude of the wave |
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20 | Speed of sound waves | Air : 330-340 m/s Water: 1400 m/s Concrete : 5000 m/s Steel: 6000 – 7000 m/s |