Using 4 exclusive-OR gates and a 4-bit full-adders MSI circuit, construct a 4-bit parallel adder/ subtractor. Use an input select variable V so that when V = 0, the circuit adds and when V = 1, the circuit subtracts. (Hint: Use 2's complement subtraction.)

Asteam is contained in a rigid tank with a volume of 1 m3. initially, the pressure and temperature are 7 bar and 500 oc, respectively. the temperature drops due to cooling process. determine: (1) the temperature at which condensation begins in °c, (2) the fraction of the total mass that has condensed when the pressure decreased to 0.5 bar. (3) the volume in m3 occupied by saturated liquid at the final state?