If the radius of the earth were to shrink and its mass were to remain the same, the acceleration due to gravity on the surface of the earth with?
Gravitational force between two masses = Km1m2r2
Where
K is universal gravitational constant m1 and m2 are the masses r is the distance between the masses.
Now , the acceleration due to m1 being earth will be = Km1r2
If the radius decreases and the mass remains same the acceleration will increase.