1. ORIGIN OF QUATUM PHYSICSVs
CLASSICAL PHYSICS

2. OR WAVE PARTICLE DUALITY
DUAL NATURE OF LIGHT OR
WAVE PARTICLE DUALITY

3. Optical Concepts:
INTERFERENCE
DIFFRACTION
POLARIZATION

4. OTHER Concepts: BLACK BODY RADIATION PHOTOELECTRIC EFFECT
EMISSION & ABSORPTION

5. BLACK BODY RADIATION:
A black body is an ideal body which allows the whole of the incident radiation to pass into itself ( without reflecting the energy ) and absorbs within itself this whole incident radiation (without passing on the energy). This propety is valid for radiation corresponding to all wavelengths and to all angels of incidence. Therefore, the black body is an ideal absorber of incident radaition.

6. PHOTELECTRIC EFFECT:

7. The setup
An adjustable voltage is applied. Voltage can be forward or reverse biased (which slows down the electrons)
Photoelectrons return to cathode through an ammeter which records the current

8. Some experimental results:
If photoelectrons get ejected when you shine monochromatic light on the target, the current increases when you increase the intensity (brighter light = more photoelectrons)

9. Parting question...
So is light a particle?
Or is light a wave?

10. DE- Broglie wave OR
Matter wave

11. Relation between Wave like & Particle like property is given by
de Broglie wavelength
Planck’s constant