Electromagnetic radiation of wavelength `lambda` and intnesity I,when incident on a metal surface causes n,electrons to be ejected per unit time.The maximum kinetic energy of the electrons is `E_(max)`.State and explain the effect,iff any,on n and `E_(max)`.When
the wavelength `lambda` is reduced but the intesntity I is not changed.

The existence of negatively charged particle in an atom was shown by J.J. Thomson as a result of the studies of the passage of electricity through gases at extremely low pressure known as discharge tube experiments. When a high voltage of the order of 10,000 volts or more was impressed across the electrodes, some sort of invisible rays moved from the negative electrode to the positive electrode these rays are called as cathode rays. Cathode rays travel in straight path in absence of electrical and magnetic field . Cathode rays consist of material part and charged particles? Cathode rays produce X-rays and light is emitted when they strike on ZnS screen. Cathode rays penetrate through thin sheets of aluminium and other metals . They affect the photogenic plate and passes heating effect when they strike on metal foil. The raito of charge to mass i.e charge/mass is same for all the cathode rays irrespective of the gas used in the tube. The existence of positively charged particle in an atom was shown be E. Goldstein. He repeated the same discharge tube experiments by using a perforated cathode. It was observed that when a high potential difference was applied between the electrodes, not only cathode rays were produced but also a new type of rays were produced simultaneoulsy from anode moving towards cathode and passes through the holes or canal of the cathode. These termed as canal rays or anode rays. These rays travel in straight lines and consists of positively charged particles. These rays have kinetic energy and produces heating effect also. The e/m ratio of these rays is smaller than that of electrons. Unlike cathode rays, their e/m value is dependent upon the nature of the gas taken in the tube. These rays produced flashes of light on ZnS screen and can pass throughs thin metal foils. They can produce physical and chemical changes and are capable to produce ionisation in gases. For cathode rays the value of e/m:

The existence of negatively charged particle in an atom was shown by J.J. Thomson as a result of the studies of the passage of electricity through gases at extremely low pressure known as discharge tube experiments. When a high voltage of the order of 10,000 volts or more was impressed across the electrodes, some sort of invisible rays moved from the negative electrode to the positive electrode these rays are called as cathode rays. Cathode rays travel in straight path in absence of electrical and magnetic field . Cathode rays consist of material part and charged particles? Cathode rays produce X-rays and light is emitted when they strike on ZnS screen. Cathode rays penetrate through thin sheets of aluminium and other metals . They affect the photogenic plate and passes heating effect when they strike on metal foil. The raito of charge to mass i.e charge/mass is same for all the cathode rays irrespective of the gas used in the tube. The existence of positively charged particle in an atom was shown be E. Goldstein. He repeated the same discharge tube experiments by using a perforated cathode. It was observed that when a high potential difference was applied between the electrodes, not only cathode rays were produced but also a new type of rays were produced simultaneoulsy from anode moving towards cathode and passes through the holes or canal of the cathode. These termed as canal rays or anode rays. These rays travel in straight lines and consists of positively charged particles. These rays have kinetic energy and produces heating effect also. The e/m ratio of these rays is smaller than that of electrons. Unlike cathode rays, their e/m value is dependent upon the nature of the gas taken in the tube. These rays produced flashes of light on ZnS screen and can pass throughs thin metal foils. They can produce physical and chemical changes and are capable to produce ionisation in gases. Which is not true with respect to cathode rays?

The existence of negatively charged particle in an atom was shown by J.J. Thomson as a result of the studies of the passage of electricity through gases at extremely low pressure known as discharge tube experiments. When a high voltage of the order of 10,000 volts or more was impressed across the electrodes, some sort of invisible rays moved from the negative electrode to the positive electrode these rays are called as cathode rays. Cathode rays travel in straight path in absence of electrical and magnetic field . Cathode rays consist of material part and charged particles? Cathode rays produce X-rays and light is emitted when they strike on ZnS screen. Cathode rays penetrate through thin sheets of aluminium and other metals . They affect the photogenic plate and passes heating effect when they strike on metal foil. The raito of charge to mass i.e charge/mass is same for all the cathode rays irrespective of the gas used in the tube. The existence of positively charged particle in an atom was shown be E. Goldstein. He repeated the same discharge tube experiments by using a perforated cathode. It was observed that when a high potential difference was applied between the electrodes, not only cathode rays were produced but also a new type of rays were produced simultaneoulsy from anode moving towards cathode and passes through the holes or canal of the cathode. These termed as canal rays or anode rays. These rays travel in straight lines and consists of positively charged particles. These rays have kinetic energy and produces heating effect also. The e/m ratio of these rays is smaller than that of electrons. Unlike cathode rays, their e/m value is dependent upon the nature of the gas taken in the tube. These rays produced flashes of light on ZnS screen and can pass throughs thin metal foils. They can produce physical and chemical changes and are capable to produce ionisation in gases. Select the incorrect statement.

In a sample of excited hydrogen atoms electrons make transition from n=2 to n=1. Emitted quanta strike on a metal of work function 4.2eV. Calculate the wavelength in A associated with ejected electron having maximum kinetic energy

Bohr model is a system consisting of small, dense nucleus surounded by orbting electrons. The electrons travel in defined circular orbits around the nucleus for which orbital angular momentum is an itnegral multiple of h/(2pi) . While rotating in allowed orbits the electrons does not raidate energy. Electromagneitc radiations are emitted when the electrons jumps from a higher orbit (E_(n_i)) to a lower orbit (E_(n_f)) When an electron jumps from higher to lower orbit energy is:

Bohr model is a system consisting of small, dense nucleus surounded by orbting electrons. The electrons travel in defined circular orbits around the nucleus for which orbital angular momentum is an itnegral multiple of h/(2pi) . While rotating in allowed orbits the electrons does not raidate energy. Electromagneitc radiations are emitted when the electrons jumps from a higher orbit (E_(n_i)) to a lower orbit (E_(n_f)) Allowed energy of hydrogen atom in the n^(th) orbit is:

Bohr model is a system consisting of small, dense nucleus surounded by orbting electrons. The electrons travel in defined circular orbits around the nucleus for which orbital angular momentum is an itnegral multiple of h/(2pi) . While rotating in allowed orbits the electrons does not raidate energy. Electromagneitc radiations are emitted when the electrons jumps from a higher orbit (E_(n_i)) to a lower orbit (E_(n_f)) Balmer series lies in:

Bohr model is a system consisting of small, dense nucleus surounded by orbting electrons. The electrons travel in defined circular orbits around the nucleus for which orbital angular momentum is an itnegral multiple of h/(2pi) . While rotating in allowed orbits the electrons does not raidate energy. Electromagneitc radiations are emitted when the electrons jumps from a higher orbit (E_(n_i)) to a lower orbit (E_(n_f)) The radius of first orbit out of the allowed of its is:

Bohr's model of hydrogen atom In order to explain the stability of atom and its line spectra, Bohr gave a set of postulates: An electron in an atom revolves in certain circular orbit around the nucleus. These are the orbits for which mvr=(nh)/(2pi) In these allowed orbits, the electron does not radiate energy. When an electron jumps from higher energy level E_(n_2) to lower energy orbit E_(n_1) , radiation is emittd and frequency of emitted electron is given by v=(E_(n_2)-E_(n_1))/h . Further the radius of the n^(th) orbit of hydrogen atom is r=(n^2h^24piepsilon_0)/(4pi^2me^2) and energy of the n^(th) orbit is given by E_n=-13.6/n^2 eV . The ground state energy of hydroen atom is -13.6 eV. The KE and PE of the electron in this state are