Important formulae & basic concepts

Chapter: Dual nature of matter and radiation

XII Physics Energy of each photon is E h= ν

Momentum of a photon is h

p =λ

h is Planck’s constant and h = 346.63 10 .x J s

−

is the frequency

is the wavelength

ν

λ

Einstein’s photoelectric equation states

that

max 0K h= ν − φ

0φ is the work function.

The stopping potential V0 is related to

maximum kinetic energy as 0 maxeV K=

V0 is the stopping potential

Threshold frequency can be found from

work function as 0 0hφ = ν 0ν is the threshold frequency

Photoelectric equation can be written as

0 0

00

eV h

hor V

e e

= ν − φ

φν= −

de Broglie wavelength of a moving

particle is h

pλ =

is the wavelength of incident lightλ

p is the momentum

h is Planck’s constant and h = 346.63 10 .x J s

−

de Broglie wavelength of a moving

particle is 2

h

p

pKinetic energy,K =

2m

hThen =

2mK

λ =

λ

is the wavelength of incident lightλ

p is the momentum

h is Planck’s constant and h = 346.63 10 .x J s

−

K is the kinetic energy of the particle m is the mass of the particle