Series and Parallel Circuits Series vs Parallel Circuit

• Slides: 28

Series and Parallel Circuits

Series vs Parallel Circuit Series Circuit • Electrons only have one • There are MULTIPLE paths for the current to path to flow through.

Series Circuit The components are connected end-to-end, one after the other. They make a simple loop for the current to flow round.

Disadvantages of a Series Circuit + I –

Disadvantages of a Series Circuit + – I The more devices (resistors) in a series circuit, the less current passes through (dimmer bulbs).

Disadvantages of a Series Circuit + – I

Disadvantages of a Series Circuit + – If one resistor breaks (a bulb goes out) the entire series is turned off.

Series Circuit - Resistance • Total resistance goes UP with each resistor since the current has must go through each resistor. • Total Resistance = Sum of all resistors in the series Rtotal = R 1+R 2+ R 3…

Series Circuit - Current • Current = amount of charge (flow of electrons) – Like the flow of water • A current can't just disappear (appear) – Since only one path if some electrons flow through R 1, then they have to continue flowing through R 2 and R 3. – Since the Current is the same through the entire circuit IT=I 1=I 2=I 3

Series Circuit - Voltage • Voltage is the electric equivalent of water pressure. – The higher the voltage, the faster electrons will flow through the conductor. • Each component has resistance that causes a drop in voltage (reduction in voltage). • Total Voltage = The sum of voltages across each series resistors V T = V 1 + V 2 + V 3…

Series Circuit Measurement 90 V + 2 A – 2 A 50 V 10 V 30 V 2 A

I a series circuit configuration, the total resistance of the circuit is the sum of the resistance levels. 90 V + –

Series Circuit: Total Resistance 90 V + – 2 A 90 V

I a series circuit configuration, the total voltage of the circuit is the sum of the voltage levels. 90 V + 2 A – 2 A 50 V 10 V 30 V 2 A

Parallel Circuit The components are connected side-by-side.

Advantages of a Parallel Circuit + – The more devices (resistors) in a parallel circuit, does not decrease the current (does not dim bulbs).

Advantages of a Parallel Circuit + –

Advantages of a Parallel Circuit + – If one resistor breaks (a bulb goes out) the rest do not.

Parallel Circuit - Resistance • Resistors added side-by-side • The more paths, the less TOTAL resistance. 1/ Req=1/R 1+1/R 2+1/R 3 • Ex. 2 resistors in parallel with 4Ω each. • Since the circuit offers two equal pathways for charge flow, only 1/2 the charge will choose to pass through a given branch.

Parallel Circuit - Current • ALL paths are used! – The current is divides up into all branches – One branch can have more current than another branch (depends on resistance in branch). • Total current = sum of current in each path IT = I 1 + I 2 + …

Parallel Circuit - Voltage • A charge only passes through a single resistor. • Voltage drop across the resistor that it chooses to pass through must equal the voltage of the battery. • Total voltage = the voltage across each individual resistor VT = V 1 = V 2 = …

Disadvantages of a Parallel Circuit + – Adding additional resistance increase total current flow. More energy is required.

Disadvantages of a Parallel Circuit + – To protect the circuit from heat damage, a fuse maybe added to the circuit.

Disadvantages of a Parallel Circuit + – To protect the circuit from heat damage, a fuse maybe added to the circuit.

Series vs Parallel Chart Series Parallel Voltage (V) Vtot = V 1 + V 2 + V 3… Vtot = V 1 = V 2 = … Current (I) Itot=I 1=I 2=I 3 Itot = I 1 + I 2 + … Resistance (R) Req = R 1+R 2+ R 3… 1/Req=1/R 1+1/R 2+1/R 3

Series Circuit - Example • Given – Vbattery = 12 V – R 1 = 50 W, R 2 = 100 W, R 3 = 100 W • Complete the following table V = I R 1 2 3 -----------------------T

Parallel Circuit - Example • Given – Vbattery = 12 V – R 1 = 50 W, R 2 = 100 W, R 3 = 100 W • Complete the following table: V = I R 1 2 3 -----------------------T

END