Explanation:
The common-emitter amplifier is a type of transistor amplifier circuit in which the emitter terminal of the transistor is grounded and the input signal is applied to the base terminal, while the output signal is taken from the collector terminal. The load resistance in this circuit is connected between the collector and the supply voltage.

When the load resistance is increased, the following changes occur in the common-emitter amplifier circuit:

1. Decrease in collector current: As the load resistance increases, the collector current decreases because the voltage drop across the load resistance increases, which reduces the voltage available for the collector current.

2. Decrease in voltage gain: The voltage gain of a common-emitter amplifier is given by the ratio of the output voltage to the input voltage. When the load resistance is increased, the output voltage decreases due to the decrease in collector current, while the input voltage remains constant. Therefore, the voltage gain decreases.

3. Increase in output impedance: The output impedance of a common-emitter amplifier is given by the ratio of the change in output voltage to the change in output current. When the load resistance is increased, the change in output voltage for a given change in output current decreases, which increases the output impedance.

Therefore, the current gain of a common-emitter amplifier decreases as the load resistance is increased due to the decrease in collector current and voltage gain, and the increase in output impedance.