How is gravitational force of attraction between two bodies caffected if the distance between them if halfed
The force increases by a factor of 4. If we're talking about gravity, the gravitational force is a function of the masses and the square of the distance between them. As distance decreased by a factor of 2 (since it was cut in half), then the force increases by a factor of 2 squared, and that's 4. Gravitational force increases by a factor of 4 when distance between two gravimetrically attracted objects is decreased by a factor of 2 (cut in half).