North Carolina Locksmith Practice Exam

The feature that prevents the possibility of determining the combination without a physical attack is referred to as being "manipulation proof." This characteristic indicates that the lock is designed to resist efforts to deduce the combination through non-destructive means, such as listening, feeling, or other forms of manipulation that do not involve directly altering or damaging the lock itself.

Locks with this feature typically incorporate complex internal mechanisms that make it difficult, if not impossible, to ascertain the combination through techniques that rely on observation or subtle manipulation. This enhances the security of the lock by ensuring that only someone with the correct physical combination can operate it, thereby preventing unauthorized access effectively.

The other options do not convey the same level of protection against non-physical attacks. For instance, "combination secure" may imply that the combination is protected but does not specifically highlight the manipulation aspect. "Internal lockout" may refer to mechanisms involved in locking certain parts of the lock internally, while "security enhancement" is a generic term that does not specifically indicate protection against manipulation. Thus, the specific reference to being manipulation proof clearly illustrates the lock’s resilience against non-destructive attempts to gain unauthorized access.