Dual Nature of ...

The work function for photoelectric effect

The average speed of a helium atom at $$25^oC$$ is $$1.23\times 10^3 ms^{-1}$$. What is the average wavelength of helium atom at $$25^oC$$?

If the kinetic energy of a free electron is doubled, its De Broglie wavelength changes by the factor:

An electron is in an excited state in a hydrogen like atom. It has a total energy of $$-3.4\space eV$$. The kinetic energy of electron is $$'E\ '$$ and its de Broglie wavelength is $$'\lambda\ '$$

An electron of mass 'm' and charge 'w' initially at rest gets accelerated by a constant electric field 'E'. The rate of change of de-Broglie wavelength of this electron at time 't' ignoring relativistic effects is

Which one of the following graphs represents the variation of maximum kinetic energy $$(E_k)$$ of the emitted electrons with frequency $$'\upsilon\ ' $$ in photoelectric effect correctly ?

Einstein's photoelectric equation is $$E_k=hv-\phi$$. In this equation $$E_k$$ refers to :

Which metal will be suitable for a photoelectric cell using light of wavelength $$4000 \mathring {A } $$ The work functions of sodium and copper are respectively 2eV and 4eV

A proton and $$\alpha$$-particle are accelerated through the same potential difference. The ratio of their  de-Broglie wavelength will be

If the kinetic energy of a moving particle is E, then the de-Broglie wavelength is