1. allow accurate range measurement
2. allow good minimum range
3. prevent frequency changes in magnetron
4. make the returned echoes easier to distinguish from noise.

Assertion (A): The hybrid p model of a transistor can be reduced to h parameter model and vice versa.

Reason (R): Hybrid p and h parameter models are interrelated as both of them describe the same device.

Assertion (A): A self bias circuit is the most commonly used bias circuit for bipolar junction transistors

Reason (R): A self bias circuit limits the increase in collector or emitter current due to change in junction temperature.

Assertion (A): In India we use CCIR-B standard

Reason (R): Video signals are frequency modulated.

1. In BPSK we deal individually with each bit of duration T_b
2. In QPSK we lump two bits to form a symbol
3. In both BPSK and QPSK signal changes occur at bit rate
4. In QPSK the symbol can have any one of four possible values