If we consider the Earth to be a perfect sphere, then the acceleration due to gravity at its surface is given by g=GR2M​Here, M is the mass of Earth; R is the radius of the Earth and G is universal gravitational constant.If the radius of the earth is decreased by 1%, then the new radius becomesR′=R−100R​=10099​R⇒R′=0.99R  New acceleration due to gravity will be given Hence, the value of the acceleration due to gravity increases when the radius is decreased.Percentage increase in the acceleration due to gravity is given by​gg′−g​×100=g0.02g​×100=2%​