Electric Charge...

Below figure shows a closed surface which intersects a conducting sphere. if a positive charge is placed at $$P,$$ the flux of the electric field through the closed surface 

In an electroscope, if aluminium strips are replaced by plastic strips, and a charged object is touched with the metal top of the electroscope:

A point charge $$ + 20\mu C$$ is at a distance 4 cm above the center of a square of side 8 cm. What is the magnitude of electrostatic flux through the square?

Two point charges $$+q$$ and $$-q$$ are held fixed at $$(-d,0)$$ and (d,0) respectively of a coordinate system$$,$$ then 

Two etalic spheres of radii $$1 CM$$ and $$3 CM$$ are given charges of $$ - 1 \times {10^{ - 2}}C$$ and $$5 \times {10^{ - 2}}C,$$ respectively. If these are  connected by a conducting wire, the final charge on the bigger sphere is :-

There are two charges $$+1\,\mu\,C + 5\,\mu\, C$$. The ratio of the forces acting on them will be 

A flat square surface with sides of length L is described by the equations $$x = L,0 \le y \le L,0 \le z \le L$$. the electric flux through the square due to a positive point charge $$q$$ located at the origin $$\left( {x = 0,y = 0,z = 0} \right)$$

Among two disc A and B first have radius 10 centimetre and charge $$10^{-6} C$$ and second have radius 30 centimetre and charge $$10^{-5} C$$. When they are touched, chanrge on both $$q_A$$ and $$q_B$$ respectively will be

Two point charges $$2C$$ and $$-6C$$ attract each other with a force of $$12N$$.A negative of $$2C$$ is added to each of the above charges, now the force between them is:

Two equipotential spherical surface having potential $$20\ V$$ and $$0\ V$$ are as shown in figure. There is no charge anywhere in space except on the surface of both the spheres. Then which  of the following figure represents the nature of electric field in region between the spherical surface by electric lines of forces.