Calculating Output Voltage of an Amplifier with RC Coupling Network

[Duckshot]

Hi I am struggling to answer this question:

The input coupling circuit of the amplifier shown in the figure consist of an RC network, with R = 1 kW and C = 5mF fed by a sinusoidal voltage source of r.m.s. amplitude of 200 mV. Assuming that the input impedance of the amplifier is, at all frequencies, so much larger than 1 kW that it can be neglected, calculate the output voltage Vo at 10Hz, 100Hz and 1kHz.

I would really appreciate any help, or if someone could point me in the right direction.

Thanks in advance

 

[Redbelly98]

Don't know if you're still working on this, I just saw it.

What are the impedances of the resistor and of the capacitor?

 

[Mene]

for any assistance.

I would approach this problem by first understanding the basics of RC coupling networks. RC coupling is a method of connecting two stages of an amplifier using a resistor and capacitor in series. This allows for the amplification of an AC signal while blocking the DC component.

To calculate the output voltage of an amplifier with an RC coupling network, we need to use the following formula:

Vo = Vin * (1 + (R2/R1))

Where Vin is the input voltage and R2 and R1 are the resistances in the RC network. In this case, R1 is the 1 kW resistor and R2 is the input impedance of the amplifier, which can be neglected as stated in the question.

So, for 10 Hz, we can calculate the output voltage as:

Vo = 0.2 V * (1 + (0/1)) = 0.2 V

For 100 Hz, we can use the same formula:

Vo = 0.2 V * (1 + (0/1)) = 0.2 V

And for 1 kHz, we get:

Vo = 0.2 V * (1 + (0/1)) = 0.2 V

This means that the output voltage will remain the same at all three frequencies, as long as the input impedance of the amplifier is significantly larger than 1 kW.

However, if the input impedance was not negligible, we would need to take it into account in our calculations. In that case, the formula for Vo would be:

Vo = Vin * (1 + (R2/R1 + R2))

I hope this helps guide you in the right direction. It's always important to understand the basic principles and formulas involved in a problem before attempting to solve it. Good luck!