Two particles with charges q1 and q2 are kept at a certain distance to exert force F on each other. If the distance is reduced to one-fifth, then the force between them is
Two smaller circles touch a large circle internally and pass through the center O of the larger circle. If the diameter of the bigger circle is 28 cm, thenwhat is the area of the bigger circle which is not enclosed by the two smaller circles (in sq.cm)?