Question

Difference between electromagnetic wave theory and planck's quantum theory

Answer 1

ElectroMagnetic  theory
--> Clark Maxwell gave this theory.
---> Light travels in the form of waves of very small wave length.
--->The colour of light depends upon its wavelength.
--->Energy is neither emitted or absorbed by a body constantly.
--->Energy of radiation is directly proportional to intensity of radiation.

Limitations:
--> This theory failed to explain black body radiation.

Plank's Quantum of Radiation :

---> Max Plank has given this theory.
--->Radiation has energy.
---> Radiant energy is neither emitted nor absorbed continuously but discontinuously in the form of small packets called as photons.
---> Energy of photon is related to the frequency of radiation V
E=hv
where h is Planck's constant whose value is 6.6.3 x 10⁻³⁴ joules /sec
---> whenever body emits or absorbs energy, it does in the whole number multiple of photons.E=nhvwhere n=1,2,3,4 etc.

Answer 2

The two theories Electromagnetic Wave Theory and Planck’s Quantum Theory explains the behaviour of radiation emitted from a substance. However, the key difference between Electromagnetic Wave Theory and Planck’s Quantum Theory is that the Electromagnetic Wave Theory does not explain the black body radiation phenomena and photoelectric effect whereas the Planck’s Quantum Theory does explain the black body radiation phenomena and the photoelectric effect.