Dual Nature of ...

The figure shows graph between stopping potential (along $$y$$-axis) and incident frequency (along x-axis) for different target metal $$A, B, C$$ and $$D$$. Let $$\displaystyle \phi _{A},\phi _{B},\phi _{C}\: and\: \phi _{D} $$are the work function of different target metals $$A, B, C$$ and $$D$$ respectively Then the correct rank of work function of different target metals is

The de-Broglie wavelength of an electron (mass $$1\times { 10 }^{ -30 }kg$$, charge$$=1.6\times { 10 }^{ -19 }\ C$$) with kinetic energy of $$200eV$$ is: (Planck's constant $$6.6\times { 10 }^{ -34 }J$$):

An LED (Light Emitting Diode) is constructed from a p-n junction based on a certain $$Ga-As-P$$ semi-conducting material whose energy gap is $$1.9eV$$.What is the wavelength of the emitted light?

The force on a hemisphere of radius $$1$$ cm if a parallel beam of monochromatic light of wavelength $$500$$ nm. falls on it with an intensity of $$0.5$$ W/cm$$^{2}$$, striking the curved surface in a direction which is perpendicular to the flat face of the hemisphere is:

A photon of energy $$4\ eV$$ is incident on a metal surface whose work function is $$2\ eV$$. The minimum reverse potential to be applied for stopping the emission of electrons is :

The de-Broglie wavelength of an electron moving with a velocity of $$1.5\times 10^8\ m/s$$ is equal to that of a photon. The ratio of kinetic energy of the electron to that of the photon $$(c=3\times 10^8\ m/s)$$:

The de-Broglie wavelength of an electron is the same as that of a $$50 keV$$ X-ray photon. The ratio of the energy of the photon to the kinetic energy of the electron is (the energy equivalent of electron mass is $$0.5 MeV$$):

The ratio of the deBroglie wave length for the electron and proton moving with same velocity is:

The de-Broglie wavelength of a free electron with kinetic energy $$'E'$$ is $$\displaystyle \lambda $$. If the kinetic energy of the electron is doubled, the de-Broglie wavelength is:

What is the wavelength of light emitted when the electron in a hydrogen atom undergoes a transition from an energy level with $$n = 4$$ to an energy level with $$n = 2?$$