Electric Charge...

Consider an electric field $$\bar { E } =E_{ 0 }\hat { x }$$ where $$E_{0}$$ is a constant. The flux through the shaded area (as shown in the figure) due to this field is

If two like charges of magnitude $$1\times {10}^{-9}$$ coulomb and $$9\times {10}^{-9}$$ coulomb are separated by a distance of $$1$$ meter, then the point on the line joining the charges, where the force experinced by a charge placed at that point is zero, is:

Three equal charges (q) are placed at corners of equilateral triangle . The force on any charge is

Two small identical spheres having charges $$+10\mu C$$ and $$- 90\mu C$$ attract each other with a force of $$F$$ Newton. If they are Kept in contact and then separated by the same distance, The new force between them is:

A charge particle $$q$$ is shot from a large distance with speed $$v$$ towards a fixed charge particle $$Q$$. It approaches $$Q$$ upto a closest distance $$r$$ and then turns. If $$q$$ were given a speed $$2v$$ the closest distance of approach would be:

Two equal and like charges when placed 5 cm apart experience a repulsive  force of 0.144 newton. The magnitude of the charge in microcoloumb will be :

Three charge +4q, Q and q are placed in a straight line of length $$l$$ at points distance 0, $$\dfrac{l}{2}$$ and $$l$$ respectively. What should be the value of Q in order to make the net force on q to be zero?

 A point charge Q is placed at origin O. Let $$\overrightarrow {{E_A}} $$,$$\overrightarrow {{E_B}} $$ and $$\overrightarrow {{E_C}} $$ represent electric fields at A, B and C respectively. If coordination of A,B and C are respectively (1,2,3) m,(1,1,-1) m and (2,2,2) m  then 

A point charge is placed at the corner of a cube. The electric flux through the shaded surface is 

Charge Q is uniformly distributed over a ring of radius r .Electric field at a point on the axis is maximum at a distance x from the centre. x is equal to