Assistant General Science

Physics – 03

പ്രകാശം, അതിൻറെ ഘടകവർണ്ണങ്ങൾ, നിയമങ്ങൾ, ഫോട്ടോ ഇലക്ട്രിക് എഫക്ട് തുടങ്ങിയ ഭാഗങ്ങളാണ് ഇന്നത്തെ പാഠത്തിൽ ഉൾപ്പെടുത്തിയിരിക്കുന്നത് .

  • Study of light



  • Speed of light

3 x 10^8


  • Time taken by Sunlight to reach Earth

8 Minute 20 Seconds (500 Sec)


  • Time taken by Moonlight to reach Earth

1.3 Seconds


  • Light travels fastest in



  • Light is an example of which wave type

Transverse wave


  • Speed of light was first measured by

Ole Christian Romer


  • Speed of light is least in which medium



  • Density of light is maximum in which medium



  • Density of light is minimum in which medium



  • Particles which travels faster than light



  • Tachyons were discovered by

ECG Sudarshan


  • Scientist who proved that light is an electromagnetic wave

Henrich Hertz


  • Unit of wavelength of light



  • Order of speed of light in different medium is



  • Rainbow is always formed in

Opposite direction of Sun


  • The Direction in which the rainbow is formed in morning



  • Color of sky in moon



  • Reason for black Color of sky in moon

Absence of atmosphere


  • When a Red flower is observed through blue glass plate it appears as



  • Color of Green leaf in red light



  • Color which is highly sensitive to human eye



  • Color which is used in danger signals



  • Color which is used Scientific labs for indicating danger



  • Color used in fog lamp of vehicles



  • Corpuscular theory of Light was proposed by

Issac Newton


  • Wave theory of Light was proposed by

Christian Huygens


  • Scientist who discovered that Sun Light consists of 7 colours

Issac Newton


  • Scientist who discovered that the light fastest in vacuum

Leon Foucault


  • Principle of three primary colours was proposed by

Thomas Young


  • Scientist who discovered that constituent colours join together to form composite light

Issac Newton


  • Electromagnetic wave theory was formulated by

James Clerk Maxwell


  • Scientist who proved that light is an electromagnetic wave

Henrich Hertz


  • Phenomenon of emission of electrons from a metal surface such as Sodium or Potassium when light ray falls on it is known as

Photoelectric effect


  • Photoelectric effect was proposed by

Henrich Hertz


  • Photoelectric effect was explained by

Albert Einstein


  • The law of Photoelectric effect was formulated by

Albert Einstein


  • Photoelectric effect was explained by Einstein on the basis of

Quantum theory


  • Photoelectric effect cannot be explained on the basis of

Electromagnetic theory


  • In 1921 Albert Einstein got Nobel prize for

Photoelectric effect


  • Number of colours in visible light

7 (VIBFYOR-Violet, Indigo, Blue, Green, Yellow, Orange and Red)


  • Primary colours are

Red, Blue and Green


  • Secondary colours are

Yellow, Magenta and Cyan


  • Primary colours used in television are

Red, Blue and Green


  • Primary colour pigments used in printing are

Yellow, Magenta, Cyan


  • Colors obtained by mixing any two Primary colours are

Secondary Colors


  • Green+Red=Yellow
  • Blue+Red= Magenta
  • Blue+Green= Cyan
  • Any two colours which combined together to form white colour is called

Complementary Colors


  • Green+Magenta=White
  • Blue+Yellow= White
  • Red+Cyan= White
  • Combining three primary colours we get



  • Distance between Sun and Earth is expressing in

Astronomical Unit


  • Wavelength of visible light

400-700 nanometer

(To be Continued…)