AC is when the electrons flow in two directions, from the positive to the negative terminal and from the negative to the positive terminal, 'alternating' between the two directions. A lot of people think of electron flow as electrons moving along a wire freely like cars go down a highway.
To check the status of protected mode, choose File > Properties > Advanced > Protected Mode. Protected mode is enabled by default. To specify the settings, do the following: Choose Edit > Preferences. In the Categories list on the left, select Security (Enhanced). In the Sandbox Protections section, select or deselect Enable Protected Mode At Startup. Enable Create Protected Mode Log File to record events. The changes take effect the next time you start the application.
Security settings. Some security settings in OS X may contribute to the inability to boot to Safe Mode. If you have Apple's FileVault disk encryption technology enabled, or if you have a firmware password set on your system, then the computer will not boot to Safe Mode.To enter Safe Mode, you must first disable these options.f your Mac is experiencing problems running, one step for determining the problem is to boot the system into Safe Mode, which is a limited environment that only loads Apple-provided software for basic functionality.