If the Sun were to collapse into a black hole, the point of no return for an investigator would be approximately 3 km from the center singularity. Would the investigator be able to survive visiting even 300 km from the center?

1.97*10⁴N .He cannot survive.

Explanation:

The Tidal force can be defined as the difference in force between center of  two bodies like center of earth and other bodies.This force stretches  the body too and fro from the center of mass of another body due to the difference in the gravitational force.

The tidal force is responsible for various phenomena like ocean tides,celestial body tearing up.

The tidal force is the effect of massive body gravitationally affecting another body.

The tidal force is the difference between the gravitational force of two bodies and directly proportional to the mass of body affecting another body and inversely proportional to the square of radius of the distance between center and the object.

Here let us consider height of person as 2m and d=1m

  ΔF= -

       =GMm[-]

         =(6.67*10⁻¹¹)(1.99*10³⁰)(1.0)[-}

   ΔF=1.97*10⁴N.

Thus he cannot survive

the higher the current the higher the mag field around it the higher the influence on the compass