Presentation on theme: "Series wiring means that the devices are connected in such a way that there is the same electric current through each device. One loop only for the flow."— Presentation transcript:
Series wiring means that the devices are connected in such a way that there is the same electric current through each device. One loop only for the flow of electricity.
1. The current in all parts of a series circuit has the same magnitude: I T = I 1 = I 2 = I 3 = etc.
2. The sum of all the separate drops in potential around a series circuit is equal to the applied emf: = V 1 + V 2 + V 3 + etc.
3. The total resistance in a series circuit is equal to the sum of the separate resistances: R T = R 1 + R 2 + R 3 + etc.
When resistors are connected in series, I is constant, the V is divided between the resistors (V 1 +V 2 = V), and the equivalent resistance R S is the sum of the individual resistances (R S = R 1 + R 2, etc.).
A 6.00-Ω resistor and a 3.00-Ω resistor are connected in series with a 12.0-V battery. Assuming the battery contributes no resistance to the circuit, find the current in the circuit.
Parallel wiring means that the devices are connected in such a way that the same voltage is applied across each device. There is more than one pathway in which the current flows.
1.The total current in a parallel circuit is equal to the sum of the currents in the separate branches. I T = I 1 + I 2 + I 3 + etc.
2. The potential difference across all branches of a parallel circuit must have the same magnitude. V T = V 1 = V 2 = V 3 = etc.
3. The reciprocal of the equivalent resistance is equal to the sum of the reciprocals of the separate resistances in parallel. 1/R Eq = 1/R 1 + 1/R 2 + 1/R 3 + etc.
When two resistors are connected in parallel, each receives current as if the other were not present. This results in the equivalent resistance being less than either resistance R 1 or R 2. 1/R P = 1/R 1 + 1/R 2 + etc.
Two speakers connected in parallel have an ac voltage of 6.00 V. The main speaker resistance is 8.00 Ω, the remote speaker resistance is 4.00 Ω. Determine (a) the equivalent resistance of the two speakers, (b) the total current supplied by the receiver, (c) the current in each speaker.
Circuits are often wired partially in series and partially in parallel. This can be a big mess, but we must learn it anyway. (At least I’m honest.)
Three resistors are connected in a circuit as shown. Determine the current in one of the 16-Ω resistors.
Kirchhoff’s Rules can be used to analyze circuits where individual groups cannot be combined. The two rules are the junction rule and the loop rule.
The junction rule states that the total current directed into a junction must equal the total current directed out of the junction.
The loop rule states that for a closed circuit loop, the total of all the potential rises is the same as the total of all the potential drops.