
In Millikan's experiment, static electric charge on the oil drops has been obtained by shining -rays. If the static electric charge on the oil drop is , calculate the number of electrons present on it.

Important Questions on Structure of Atom








Two non-conducting solid spheres of radii and , having uniform volume charge densities and , respectively, touch each other. The net electric field at a distance from the centre of the smaller sphere, along the line joining the centres of the spheres, is zero. The ratio can be


A thin disc of radius has a concentric hole of radius in it (see figure). It carries uniform surface charge on it. If the electric field on its axis at a height from its centre is given as then the value of is





Electrons in a cathode ray tube have been emitted with a velocity of . The number of following statements which is/are true about the emitted radiation is
Given :
(A ) The deBroglie wavelength of the electron emitted is
(B ) The characteristic of electrons emitted depend upon the material of the electrodes of the cathode ray tube.
(C) The cathode rays start from cathode and move towards anode.
(D ) The nature of the emitted electrons depends on the nature of the gas present in cathode ray tube..


Match List (Experiment performed) with List (Phenomena discovered/associated)and select the correct option from the options given below the lists
List-I | List-II | ||
---|---|---|---|
Davisson and Germer experiment | Wave nature of electrons | ||
Millikan's oil drop experiment | Charge of an electron | ||
Rutherford experiment | Quantisation of energy levels | ||
Franck-Hertz experiment | Existence of the nucleus |








