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1.
When a monochromatic point source of light is at a distance of 0.2 m from a photoelectric cell, the cut off voltage and the saturation current are respectively 0.6 volt and 18.0 mA. If the same source is placed 0.6 m away from the photoelectric cell, then find
(a) the stopping potential
(b) the saturation current
2.
663 mW of light from a 540 nm source is incident on the surface of a metal. If only 1 of each 5 × 109 incident photons is absorbed and causes an electron to be ejected from the surface, the total photocurrent in the circuit is ________.
3.
Light of wavelength 330 nm falling on a piece of metal ejects electrons with sufficient energy which requires voltage V0 to prevent a electron from reading collector. In the same setup, light of wavelength 220 nm, ejects electrons which require twice the voltage V0 to stop them in reaching a collector. Find the numerical value of voltage V0.(Take plank's constant, h = 6.6 × 10–34 Js and 1 eV = 1.6 × 10–19 J)
4.
A small 10W source of ultraviolet light of wavelength 99 nm is held at a distance 0.1 m from a metal surface. The radius of an atom of the metal is approximately 0.05 nm. Find
(i) the average number of photons striking an atom per second.
(ii) the number of photoelectrons emitted per unit area per second if the efficiency of liberation of photoelectrons is 1%.
5.
The surface of cesium is illuminated with monochromatic light of various wavelengths and the stopping potentials for the wavelengths are measured. The results of this experiment is plotted as shown in the figure. Estimate the value of work function of the cesium and Planck’s constant.
6.
The frequency and the intensity of a beam of light falling on the surface of photoelectric material are increased by a factor of two. Treating efficiency of photoelectron generation as constant, this will :
(A) increase the maximum energy of the photoelectrons, as well as photoelectric current by a factor of two.
(B) increase the maximum kinetic energy
When a monochromatic point source of light is at a distance of 0.2 m from a photoelectric cell, the cut off voltage and the saturation current are respectively 0.6 volt and 18.0 mA. If the same source is placed 0.6 m away from the photoelectric cell, then find
(a) the stopping potential
(b) the saturation current
2.
663 mW of light from a 540 nm source is incident on the surface of a metal. If only 1 of each 5 × 109 incident photons is absorbed and causes an electron to be ejected from the surface, the total photocurrent in the circuit is ________.
3.
Light of wavelength 330 nm falling on a piece of metal ejects electrons with sufficient energy which requires voltage V0 to prevent a electron from reading collector. In the same setup, light of wavelength 220 nm, ejects electrons which require twice the voltage V0 to stop them in reaching a collector. Find the numerical value of voltage V0.(Take plank's constant, h = 6.6 × 10–34 Js and 1 eV = 1.6 × 10–19 J)
4.
A small 10W source of ultraviolet light of wavelength 99 nm is held at a distance 0.1 m from a metal surface. The radius of an atom of the metal is approximately 0.05 nm. Find
(i) the average number of photons striking an atom per second.
(ii) the number of photoelectrons emitted per unit area per second if the efficiency of liberation of photoelectrons is 1%.
5.
The surface of cesium is illuminated with monochromatic light of various wavelengths and the stopping potentials for the wavelengths are measured. The results of this experiment is plotted as shown in the figure. Estimate the value of work function of the cesium and Planck’s constant.
6.
The frequency and the intensity of a beam of light falling on the surface of photoelectric material are increased by a factor of two. Treating efficiency of photoelectron generation as constant, this will :
(A) increase the maximum energy of the photoelectrons, as well as photoelectric current by a factor of two.
(B) increase the maximum kinetic energy