Name: de Broglie Hypothesis
Uploaded: 2019-07-19
Duration: 11 min 28 s
Description: The De Broglie hypothesis proposes that all matter exhibits wave-like properties and relates the observed wavelength of matter to its momentum. Let's learn.

Question

Describe an experiment to study the effect of frequency of incident radiation on stopping potential.

Accepted Answer

To study the relation between the frequency of the incident radiation and the stopping potential, suitably adjust the same intensity of light radiation at various frequencies and study the variation of photocurrent with collector plate potential.

The resulting variation is shown in figure. Different values of stopping potential are obtained but the same value of the saturation current for incident radiation of different frequencies. The energy of the emitted electrons depends on the frequency of the incident radiations. The stopping potential is more negative for higher frequencies of incident radiation. Note from figure that the stopping potentials are in the order,

$V_{o 3} > V_{o 2} > V_{o 1}$

where frequencies are in the order $ν_{3} > ν_{2} > ν_{1}$

This implies that greater the frequency of incident light, greater is the maximum kinetic energy of the photoelectrons. Consequently, we need greater retarding potential to stop them completely. If we plot a graph between the frequency of incident radiation and the corresponding stopping potential for different metals we get a straight line.

Describe an experiment to study the effect of frequency of incident radiation on stopping potential.

Important Questions on Dual Nature of Radiation and Matter

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