The measurement quoted in dB describes the ratio (10 log power difference, 20 log voltage difference, etc.) between the quantity of two levels, the level being measured and a reference.
Alt Codes for Bracketing ; Alt Code Symbol Description Alt 40 ( Open Bracket Alt 41 ) Close Bracked Alt Codes for Degree of Accuracy ; Alt Code Symbol Description Alt 241 Â± Plus or Minus Alt Codes for Fractions ; Alt Code Symbol Description Alt 47 / Fraction seperator
Control-Alt-Delete is a computer keyboard command on IBM PC compatible computers, invoked by pressing the Delete key while holding the Control and Alt keys: Ctrl+Alt+Delete. The function of the key combination differs depending on the context but it generally interrupts or facilitates interrupting a function. For instance, in pre-boot environment or in DOS, Windows 3.0 and earlier versions of Windows or OS/2, the key combination reboots the computer. Starting with Windows 95, the command invokes