Electrical Engineering - Series-Parallel Circuits - Discussion

The output is measured across the load, if we assume ideal condition, the circuit with 0 resistance in wires, the entire voltage drops across the load so output voltage should remain constant.

When there is no load there is no current hence the internal resistance drop is zero. But when we connect a load current starts flowing. Hence some vol drop will appear across the internal resistance.

Vo = Vs (with no load).

By voltage divider.
Vo = Vs(R/(R+RL)) (with load).

RL = across the load.

So the Voltage OUTPUT WILL DECREASE!

ASSUME A VALUE SO THAT YOU WILL UNDERSTAND!

Assuming that from a voltage divider circuit with two resistors given (R1 and R2), we added a load resistance RL parallel to R2, making it a simple series-parallel circuit.

Note that (R2 parallel to RL) will decrease the total resistance.

1. Decreasing the total resistance will increase the total current drawn from the source: IT = 'VT/RT".
2. If the current drawn from the source increase, the current across R1 will also increase.
3. Consequently, the voltage drop across R1 will also increase, leaving less voltage for the output.
4. Therefore, the readings across Vo will decrease.