I=v/r. If r is 0. Current will be very high in theory.
Are you using this bolt to serve as a grounding point for equipment installed in your facility ?
Be aware that to be properly used as a grounding point, that bolt must be electrically connected (bonded) to the rebar within the concrete.
Usually the bolts used for this purpose are large enough to handle the fault currents that a circuit breaker will trip on.
You would need more information. Unless the wall is wet it would likely be more than enough of an insulator so no current would flow as the bolt is not grounded.
Assume " almost dry wall " has about 1M ohm resistance between earth ground and bolt.
Therefore, current is about 0.25mA
It is sufficient to light up a neon tester.
very little to none... ignoring factors such as gradient grounding, the cement is a poor conductor of current so the flow stops at the bolt.
In all likelyhood the answer you are supposed to come up with is Zero
It depends on the circuit impedances and the circuit protection.
