The ratio of the forces between two small spheres with constant charges, F1 in air and F2 in a medium of dielectric constant K, is

The ratio of the forces between two charges placed at a certain distance apart in air at half of the distance apart in medium of dielectric .k. is

Two point charges placed at a distance r in air experience a certain force. Then the distance at which they will experience the same force in a medium of dielectric constant K is

Two point charages placed at a distance r. in the air experiene a certain force. Then the distance at which they will experience the same force in the medium of dielectric constant K is

Two charges exert a force of 10 N on each other when separated by a distance 0.2 m in air. When they are placed in another medium of dielectric constant K = 4 , and separated by distance R. they exert same force. The distance R equats to

The force between two small charged spheres having charges of 1xx10^(-7)C and 2xx10^(-7)C placed 20 cm apart in air is

Two point charges placed at a distance r in air exert a force F on each other. The value of distance R at which they experience force 4F when placed in a medium of dielectric constant K = 16 is :

What is the force between two small charged of 2 xx 10^(-7) C placed 30 cm apart in air?

What is the force between two small charged spheres having charges of 2xx10^(-7)C and 3xx10^(-7) C placed 30cm apart in air ?

Two similar point charges q_1 and q_2 are placed at a distance r apart in the air. The force between them is F_1 . A dielectric slab of thickness t(ltr) and dielectric constant K is placed between the charges . Then the force between the same charge . Then the fore between the same charges is F_2 . The ratio is

Force between two identical charges placed at a distance of r in vacuum is F .Now a slab of dielectric constant 4 is inserted between these two charges . If the thickness of the slab is r//2 , then the force between the charges will becomes