Chapter : 11
What are Dual Nature Of Radiation And Matter ?
Topic Name  Formula  Symbol Representation  Important Points 
Photon Theory of Light  E = hv=(hc/λ)joule or E =(hc/λ) =(1240/λ)eVnm  E = Energy of photon, h = Planck’s constant, v = Frequency of photon c = Speed of light λ = Wavelength of photon e = Charge of electron  
Intensity of Light  I =(E/At)=(P/A)  I = Intensity of light E = Incident energy t = Time taken A = Area of surface P = Power of source 

Work Function  Φ=hv_{Φ}=(hc/λ_{0})  Φ = Work function h = Planck’s constant V_{o} = Threshold frequency λ_{o} = Threshold wavelength 

Topic Name  Formula  Symbol Representation  Important Points 
Einstein’s equation of photoelectric effect  hv = k_{max} + Φ_{0} or k_{max} = h – Φ_{0} or ev_{0} = hv – hv_{0}  h = Planck’s constant v = Frequency of the incident photon k_{max} = Maximum kinetic energy of ejected electrons Φ_{0} = Work function of the metal U_{0} = Stopping potential V_{0} = Threshold frequency e = Charge on electron  • According to Einstein, photon energy is utilized for two purposes, partly for getting the electrons free from the atom and away from the metal surface known as the work function of the metal (Φ_{0}) and the remaining photon energy is used up in providing the electrons kinetic energy of (1/2)mv^{2} 
deBroglie Hypothesis of Matter Waves  λ=(h/p)=(h/mv)=(h/√2mE)  λ = deBroglie wavelength or wavelength associated with particle p = momentum of the particle m = mass of the moving particle v = velocity of the moving particle E = kinetic energy of the moving particle  • According to deBroglie hypothesis, a moving particle sometimes acts as a wave and sometimes as a particle. The wave associated with waving particle is called matter waves or deBroglie waves. 