The acceleration you would experience is:
$a=(GM)/r^2$
Where $M=10^11kg$ is the mass of the black hole, $G=6.674m^2kg^(-1)s^(-2)$ is the gravitational constant and $r$ is the distance from the black hole.
The acceleration due to gravity on Earth is $a=9.81ms^(-2)$.
So, to experience 1g of acceleration, thee distance is:
$r^2=(GM)/a=6.67/9.81$
This gives $r=0.82m$.
Being so close to a black hole puts you in the region where tidal effects can occur. At $r=0.6m$, $a=18.5ms^(-2)$. At $r=0.4m$, $a=41.7ms^(-2)$.
Incidentally, the Schwarzschild radius for a black hole is given by:
$r=(GM)/c^2$
Where $c$ is the speed of light. A black hole with a mass of $10^11kg$ has a radius of $7.4*10^(-17)m$, which is slightly smaller than $10^-16m$.
