Not as "light" as it looks

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In photoelectric effect, we have the equations for particle nature of light i.e., for photons,

$p = \frac{h}{\lambda}$ $E = pc$

where,
$p$ is the momentum of a photon
$E$ is the energy of a photon
$c$ is the speed of light in air
$h$ is the Planck's constant
$\lambda$ is the wavelength of the light

Hence we can conclude that ,

Photons with equal momenta necessarily have equal energies and equal wavelengths All of these Photons with equal wavelengths necessarily have equal momenta and equal energies Photons with equal energies necessarily have equal wavelengths and equal momenta

1 solution

Anish Puthuraya
Jan 31, 2014

Note: Almost exactly same problem has been mentioned in HC Verma Part 2

All the options are correct only when magnitudes are considered. Since this is not the case,
there is only one answer

Momentum is a vector. Thus,
if the momenta is same, then Energy and wavelengths are same.

But,
if any other quantity is same, then it does not ensure that the direction of the momentum vector is also same.

RIGHT . $\sum_{i=1}^\infty (\sqrt{Momentum is a VECTOR QUANTITY})$

Anirudha Nayak - 7 years, 4 months ago

Not as "light" as it looks

1 solution

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