Regarding Operating systems, what causes a process to generate a trap when it is interrupted by a timer interrupt?

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When a process is interrupted by a timer interrupt, it is because the time slice allocated to the process has expired. The operating system generates a trap to the process to inform it that its time slice has ended and it must relinquish the CPU to other processes. This trap is generated by the system timer, which is a hardware device that generates periodic interrupts to the operating system. When an interrupt occurs, the operating system stops the current process and saves its state, then switches to another process that is ready to run. The trap generated by the timer interrupt is handled by the operating system's scheduler, which decides which process will run next. This process is known as scheduling.