In this Video, Komal Mehna, Assistant Professor, Biyani Group of Colleges explains about the program status word (PSW) register that is an 8-bit register. It is also known as the flag register. In PSW register only 6 bits are used by the 8051 microcontroller and remaining two bits are user-defined bit. Out of six flags four of the flags are called conditional flags, which indicate some conditions after an instruction is executed. These four flags are :-
a) CY (carry), b) AC (auxiliary carry), c) P (parity), d) OV (overflow).
And RS0 and RS1 are used for register selection.

In this Video, Monika Kiroriwal, Assistant Professor, Biyani Group of Colleges explains about the RADAR, which stands for Radio Detection and Ranging and it was first introduced during 2nd world war to detect enemy aircrafts. Basically radar is a EM system to detect the range and location of the device it may be car, space, craft and natural environment. Radar transmitter generates an EM signal into free space and strike on the target and reradiates from the target in the form of echo signal. These echo signals are collected by antenna and receiver receives these signals and range of target is calculated by measuring the time taken by signal to travel to target and return back to radar.