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Series-Parallel Circuits - Engineering

Q1:

The output of a certain voltage divider is 12 V with no load. When a load is connected, the output voltage

A decreases

B increases

C remains the same

D becomes zero

ANS:A - decreases

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.