provide noise model for a resistor R, based : i) Norton equivalent circuit (2marks) ii) Thevenin equivalent circuit b) Give a suitable definition of available noise power. Then show that for resistance Rs the available thermal noise power spectral density S(Pa) is given by: S(Pa) = kT; where k is Boltzmann's constant and T is temperature in Kelvins. (5marks) c) Sketch the Thevenin equivalent noise model circuit for the circuit shown below, and use this equivalent circuit to find an expression for the output noise power across AB. (5marks) d) For the circuit shown below, find expressions for available power from the source i) ii) available power at the output with resistance Ro and voltage Eo iii) available power gain