How does the alarm work even when the mobile is switched off?
When you switch off your smartphone, you don’t actually make it dead by completely breathing out the power inside it. The first thing that happens when you switch off your phone is that the processor shuts down the Operating System.Once the OS is shut down most of the smartphones enter a mode similar to “Sleep Mode”. In sleep mode processor usually keeps an eye on the Input buttons of the device(Power, Volume Up and Down), this is similar to BIOS in PC.To turn your smartphone on when you press power the processor has to be awake and it consumes battery. A part of processor called “Timer” is also awake to listen to signals.In smartphones that provide this feature, Alarms actually are bounded with the timer.So as long as the timer is ON, the device can ring alarms for you and save your date and time in the memory.This is how the alarm works even when the mobile is switched off.Note: when you remove your battery your mobile can’t do anything as it doesn’t have CMOS kind of arrangement, like the ones we see in PC and laptops.So this was Shubham Habib (Founder of HackerzTrickz)Signing off!