4 Analyse the circuit shown in Figure 1 (a) to find VOUT. You should find that VOUT is 4 V.

If a load resistor, R₁ of 13 ohms is connected between nodes A and B as shown in (b) then what value will the supply voltage, Vs need to be changed to such that VOUT is maintained at 4 volts? Calculate your answer in volts to one decimal place but do not enter the units in your answer. For example if the new value of Vs is 28.4 volts you would enter 28.4 only.