The work function of a metal is $1.6\times {10}^{-19}$ J. When the metal surface is illuminated by the light of wavelength 6400 Å, then the maximum kinetic energy of emitted photo-electrons will be
(Planck's constant = $6.4\times {10}^{-34 }\mathrm{Js}$) 

Ultraviolet radiations of 6.2 eV falls on an aluminium surface (work function 4.2 eV ). The kinetic energy in joules of the fastest electron emitted is approximately

The work function for tungsten and sodium are 4.5 eV and 2.3 eV respectively. If the threshold wavelength $\mathrm{\lambda }$ for sodium is 5460 Å, the value of $\mathrm{\lambda }$ for tungsten is

A photon of energy 3.4 eV is incident on a metal having work function 2 eV. The maximum K.E. of photo-electrons is equal to:

The photoelectric threshold wavelength for a metal surface is 6600 Å. The work function for this is 

Photoelectric effect was successfully explained first by

A photo cell is receiving light from a source placed at a distance of 1 m. If the same source is to be placed at a distance of 2 m, then the ejected electron:

In a photoelectric experiment for 4000 Å incident radiation, the potential difference to stop the ejection is 2 V. If the incident light is changed to 3000 Å, then the potential required to stop the ejection of electrons will be

(2) Less than 2 V

Light of wavelength 4000 Å is incident on a sodium surface for which the threshold wave length of photo – electrons is 5420 Å. The work function of sodium is

Photocell is a device to: 

The ratio of de-Broglie wavelengths of molecules of hydrogen and helium which are at temperature 27 $°\mathrm{C}$ and 127 $°\mathrm{C}$ respectively is

A photon of wavelength 6630 Å is incident on a totally reflecting surface. The momentum delivered by the photon is equal to

If the work function for a certain metal is $3.2\times {10}^{-19}$ joule and it is illuminated with light of frequency $8\times {10}^{14}$ Hz. The maximum kinetic energy of the photo-electrons would be $\left(\mathrm{h}=6.63\times {10}^{-34} \mathrm{Js}\right)$
(a) $2.1\times {10}^{-19} \mathrm{J}$              (b) $8.5\times {10}^{-19} \mathrm{J}$ 
(c) $5.3\times {10}^{-19} \mathrm{J}$              (d) $3.2\times {10}^{-19 }\mathrm{J}$

The stopping potential for photoelectrons:

The maximum wavelength of radiation that can produce photoelectric effect in a certain metal is 200 nm. The maximum kinetic energy acquired by electron due to radiation of wavelength 100 nm will be 

When the light source is kept 20 cm away from a photo cell, stopping potential 0.6 V is obtained. When source is kept 40 cm away, the stopping potential will be 

The minimum energy required to remove an electron is called 

Assuming photoemission to take place, the factor by which the maximum velocity of the emitted photoelectrons changes when the wavelength of the incident radiation is increased four times, is 

If the work function of a metal is $\text{'}\mathrm{\varphi }\text{'}$ and the frequency of the incident light is '$\nu$', there is no emission of photoelectron if

Light of wavelength $\mathrm{\lambda }$ strikes a photo-sensitive surface and electrons are ejected with kinetic energy E. If the kinetic energy is to be increased to 2E, the wavelength must be changed to $\mathrm{\lambda }\text{'}$ where 

If in a photoelectric experiment, the wavelength of incident radiation is reduced from 6000 Å to 4000 Å, then:

The photoelectric work function for a metal surface is 4.125 eV. The cut-off wavelength for this surface is

As the intensity of incident light increases

Which of the following is dependent on the intensity of incident radiation in a photoelectric experiment

The maximum kinetic energy of photoelectrons emitted from a surface when photons of energy 6 eV fall on it is 4 eV. The stopping potential in volts is

Work function of a metal is 2.1 eV. Which of the waves of the following wavelengths will be able to emit photoelectrons from its surface ?

The cathode of a photoelectric cell is changed such that the work function changes from ${\mathrm{W}}_1$ to ${\mathrm{W}}_2$ $\left({\mathrm{W}}_2>{\mathrm{W}}_1\right)$. If the current before and after the change are ${\mathrm{I}}_1$ and ${\mathrm{I}}_2$, all other conditions remaining unchanged, then (assuming $\mathrm{h\nu }>{\mathrm{W}}_2$) :

A beam of light of wavelength $\mathrm{\lambda }$ and with illumination L falls on a clean surface of sodium. If N photoelectrons are emitted each with kinetic energy E, then 

Which of the following statements is correct

For intensity I of a light of wavelength 5000Å the photoelectron saturation current is 0.40 $\mathrm{\mu A}$and stopping potential is 1.36 V, the work function of metal is