PiTheory

Dual Nature of Radiation and Matter formulas

Class 12 physics formula sheet for NEET and JEE: the key equations of NCERT chapter 11, the special cases questions are built on, and diagrams where they help.

23 formulas4 sectionsClass 12 · Chapter 111 of 4 sections free

By Sreeraj P, M.Sc Physics · 10+ years teaching NEET and JEE

Most used formulasOther formulas and cases

1Photon

$$E=hf=\frac{hc}{\lambda},\qquad E(\text{eV})=\frac{1240}{\lambda(\text{nm})}=\frac{12400}{\lambda(\text{Å})}$$
$$\begin{array}{l}\displaystyle E=hf=\frac{hc}{\lambda}\\[6pt]\displaystyle E(\text{eV})=\frac{1240}{\lambda(\text{nm})}=\frac{12400}{\lambda(\text{Å})}\end{array}$$

$h=6.63\times10^{-34}$ J s $=4.14\times10^{-15}$ eV s; 1 eV $=1.6\times10^{-19}$ J.

$$p=\frac h\lambda=\frac Ec,\qquad m_{\text{eff}}=\frac{E}{c^2}=\frac{h}{c\lambda}$$
$$\begin{array}{l}\displaystyle p=\frac h\lambda=\frac Ec\\[6pt]\displaystyle m_{\text{eff}}=\frac{E}{c^2}=\frac{h}{c\lambda}\end{array}$$

Zero rest mass and charge (not deflected by fields). Speed $c$ in vacuum.

$$N=\frac{P\lambda}{hc}\ \text{per second},\qquad I=\frac{P}{4\pi r^2}$$
$$\begin{array}{l}\displaystyle N=\frac{P\lambda}{hc}\ \text{per second}\\[6pt]\displaystyle I=\frac{P}{4\pi r^2}\end{array}$$

Photons emitted per second by a source of power $P$; intensity ∝ number of photons per area per time. Force on a surface: $P/c$ (absorbed), $2P/c$ (reflected).

3 more sections and 17 formulas in the full chapter

  1. 2Photoelectric effect8 formulas · 2 diagrams
  2. 3Matter waves6 formulas
  3. 4X-rays3 formulas

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