In the circuits shown abow, a battery with a voltage AVbat is connected to the c
ID: 1301638 • Letter: I
Question
In the circuits shown abow, a battery with a voltage AVbat is connected to the circuit with resistances R1, R2, and R3, and a switch connected to R3. In the circuit on the left, the switch is open and in the circuit on the right the switch is closed. For which circuit, if either, will the voltage read by the wit meter be largest? The voltages are the same because when the switch is closed the resistance increases and the current decreases Switch Open (Left), because the total current is larger for this circuit O Switch Open (Left), because the total resistance is larger for this circuit Switch Open (Left), because the current is the same in both circuits and the resistance connected to the voltmeter is larger for this circuit Switch Open (Left), because the current is the same in both circuits and the resistance connected to the voltmeter is larger for this circuit Switch Open (Left), because the battery voltage is larger for this circuit Switch Closed (Right), because the total resistance is larger for this circuit Switch Closed (Right), because the total current is larger for this circuit The voltages are the same because R2 and R3 are in parallel The voltages are the same because when the switch is closed the resistance decreaseas and the current increases Switch Closed (Right), because the battery voltage is larger for this circuitExplanation / Answer
When switch is open:
Delta V ab = [ delta V bat / ( R1 + R2) ] * R2
When switch is closed:
Delta V ab = [ delta V bat / R total ] * R2 where R tot = R1 + R2*R3 / ( R2 + R3)
so, Delta Vab when the switch is closed is more than when it is open.