Final answer:
Connecting a resistive load to the output of a direct coupled amplifier causes 1. the output voltage to decrease due to the voltage drop created by the additional current drawn through the amplifier's output impedance.
Step-by-step explanation:
When a resistive load is connected to the output of a direct coupled amplifier, the output voltage of the amplifier decreases. This decrease is due to the fact that the resistive load draws current from the amplifier, which causes a voltage drop across the output impedance of the amplifier. By Ohm's law, the potential drop V across a resistor when a current flows through it is calculated using the equation V = IR, where I is the current in amps and R is the resistance in ohms.
Considering the internal resistance of the amplifier along with the connected resistive load, the overall resistance increases, which leads to a higher voltage drop, thus reducing the available output voltage to the load. Moreover, the power dissipated in the circuit would increase due to the added resistor, especially if the amplifier's power supply cannot maintain the original output voltage under the increased load.