The JFET in the circuit shown in fig. has an I_DSS = 10mA and V_p = -5V. The value of the resistance R_s for a drain current I_DS = 6.4mA is (select the Nearest value).

Assume that the operational amplifier in figure is deal the current I through the IK ohm resistor is

The bit stream 01001 is differentially encoded using 'Delay and Ex OR' scheme for DPSK transmission. Assuming the reference bit as a '1' and assigning phases of '0' and '$$\,\pi $$' for 1's and 0's respectively, in the encoded sequence, the transmitted phase sequence becomes

Coherent demodulation of FSK signal can be effected using