If the radius of earth were to shrink by one percent, its mass remaining the same, the acceleration due to gravity on the earth’s surface would:

decrease remains unchanged increase None of these

increase

= $\frac{GM}{R^2}$ $\Rightarrow \frac{d g}{g}=-\frac{2 d R}{R}$ As  $\frac{d R}{R}$ = -1% $\Rightarrow \frac{d g}{g}$= -2 (-1) = +2%. Thus due to gravity will increase.