What is the minimum energy that must be given to a H atom in ground state so that it can emit an` H_lambda` line in Balmer series?If the angular momentum of the system is conserved, what would be the angular momentum of such` H_lambda` photon?

The change in the angular momentum of the electron when it jumps from the fourth orbit to the first orbit in a H - atom is

What is the maximum number of emission lines when the excited electron of a H atom in n= 6 drops to the grounds state?

The energy of an electron in an excited state of hydrogen atom is -1.51 eV . Calculate the angular momentum of the electron in this state. h = 6.63 xx 10^-34 Js

The lambda for H_(alpha) line of Balmer series is 6500 A^@ . Thus lambda for H_(beta) line of Balmer series is

In the explanation of photoelectric effect, we assume one photon of frequency nu collides with an electron and transfers its energy. This leads to the equation for the maximum energy E_max of the emitted electron as, E_max = h nu - phi_0 whare phi_0 is the work function of the metal . If an electron absorbs two photons (each of frequency nu ) what will be the maximum energy for the emitted electron ?

With what minimum speed v must be small ball be pushed inside a smooth vertical tube from a height h so that it may reach the top of the tube?

For the ground state, the electron in the H - atom has an angular momentum=L, according to the simple Bohr model. Angular momentum is a vector and hence there will be infinitely many orbits with the factor pointing in all possible directions, In actuality this is not true,

Read the following paragraph and answer the questions given below it: The resistance of a metal falls when cooled below room temperature. Many scientists believed that the value of the resistance would become constant at some very low temperature, allowing the current to flow with little or no resistance. H. K. Onnes successfully liquefied helium in 1908 by cooling it to about 4 K. In 1911, while investigating the electrical property of very pure mercury. Onnes discovered that at a temperature of 4.2 kelvin, its resistance practically vanished. This new state, on account of its extraordinary property, is now called the superconducting state and the phenomenon is called superconductivity. A superconductor, below a certain critical temperature, offers almost zero resistance to a flow of current through it. Onnes also discovered that a superconductor exhibits persistent current: once set up, the current continues to flow for a very long time without an electric potential difference driving it and without significant loss. Superconductivity is used in many diverse areas, such as magnetically levitated trains, transmission of electricity, increasing speed of computers, in MRI (magnetic resonance imaging). At what temperature does the resistance of very pure mercury become almost zero?

Read the following paragraph and answer the questions given below it: The resistance of a metal falls when cooled below room temperature. Many scientists believed that the value of the resistance would become constant at some very low temperature, allowing the current to flow with little or no resistance. H. K. Onnes successfully liquefied helium in 1908 by cooling it to about 4 K. In 1911, while investigating the electrical property of very pure mercury. Onnes discovered that at a temperature of 4.2 kelvin, its resistance practically vanished. This new state, on account of its extraordinary property, is now called the superconducting state and the phenomenon is called superconductivity. A superconductor, below a certain critical temperature, offers almost zero resistance to a flow of current through it. Onnes also discovered that a superconductor exhibits persistent current: once set up, the current continues to flow for a very long time without an electric potential difference driving it and without significant loss. Superconductivity is used in many diverse areas, such as magnetically levitated trains, transmission of electricity, increasing speed of computers, in MRI (magnetic resonance imaging). What is a superconductor?

Read the following paragraph and answer the questions given below it: The resistance of a metal falls when cooled below room temperature. Many scientists believed that the value of the resistance would become constant at some very low temperature, allowing the current to flow with little or no resistance. H. K. Onnes successfully liquefied helium in 1908 by cooling it to about 4 K. In 1911, while investigating the electrical property of very pure mercury. Onnes discovered that at a temperature of 4.2 kelvin, its resistance practically vanished. This new state, on account of its extraordinary property, is now called the superconducting state and the phenomenon is called superconductivity. A superconductor, below a certain critical temperature, offers almost zero resistance to a flow of current through it. Onnes also discovered that a superconductor exhibits persistent current: once set up, the current continues to flow for a very long time without an electric potential difference driving it and without significant loss. Superconductivity is used in many diverse areas, such as magnetically levitated trains, transmission of electricity, increasing speed of computers, in MRI (magnetic resonance imaging). What is special about a superconductor?