# ELECTRIC CHARGES AND FIELDS

## This assignment contains very important questions of ELECTRIC CHARGES AND FIELDS

1. Explain the following terms –(a) Quantisation of charge . (b) Additivity of charge and (c) conservation of charge.
2. What is electric field lines ? Draw the field lines for (a) A positive charge (b) A negative charge (c) An electric dipole (d) Two positive charge having equal magnitude separated by some distance, (e)  ) Two positive charge having different magnitude separated  by some distance, and (f) A plane positively charged sheet (g) A positive point charge  (+q) is kept in the vicinity of an uncharged conduction plate. Sketch the electric field lines originated from the point on to the surface of the plate. Also explain why ( I ) Field lines never intersect each other? (ii) Why field lines always comes out normally to the surface ?
3. What do you mean by the term electric dipole and dipole moment? Is it scaler or vector quantity? Find the electric at a point the (i) axial  and  (ii) equatorial point , also find the relation between them . Also deduce an expression for the torque acting on a dipole and energy stored in the dipole when it is placed in the uniform electric field E .What will happen to the dipole when it is placed in non – uniform electric field?
4. State and prove Gauss theorem . Using Gauss’s theorem find the magnetic field at a point due to (i) straight charged wire , (ii) plane charged sheet , show that it is independent of distance of the point from the sheet , and (iii) charged spherical shell also plot the graph between electric field and separation of point from the centre of the shell. Using Gauss’s law also derive  an expression for the electric field between two uniformly charged  parallel sheets of charge density σ and -σ respectively
5. (i)Define electric flux  , write its SI unit . (ii)The electric field components due to a charge inside the cube of side 0.1m are shown below      Ex=αx   ,  where α =500N/C-m EY=0,EZ=0Calculate (a) The flux through the cube (b)the charge inside the cube CLICK HERE TO DOWNLOAD-Very important questions for ELECTRIC CHARGES AND FIELD