Series and parallel circuits Flashcards
In series if you disconnect one component what happens to the circuit
It is broken and will stop
What is the rule for potential difference in series circuits
Voltage is shared
Vtotal= V1 +V2 +V3…
What is the rule for current in a series circuit
Is the same everywhere
I1 = I2 = I3…
What is the rule for resistance in a series circuit
Resistance adds up
Rtotal = R1 + R2 + R3…
Why in series does resistance add up
-by adding a … in series the 2 resistors have to … the total …
-the pd … across each … is lower so the … through each … is also lower, V=….
-in series the … is the … everywhere so the … current is reduce when a … is added
-this means the … resistance of the circuit …
-by adding a resistor in series the 2 resistors have to share the total pd
-the pd difference across each resistor is lower so the current through each resistor is also lower, V=IR
-in series the current is the same everywhere so the total current is reduce when a resistor is added
-this means the total resistance of the circuit increases
What happens if you disconnect one thing in a parallel circuit
Nothing
What is the rule for potential difference in parallel circuits
Potential difference is the same for all components
V1 = V2 = V3…
What is the rule for current in parallel circuits
Current is shared between branches
Itotal = I1 + I2 + I3…
What is the rule for adding a resistor in parallel circuits
It reduces the total resistance
Why is current shared between branches in parallel circuits
-there are … where the current either … or …
-the … current going … a junction has to … the … current …
-there are junctions where the current either splits or rejoins
-the total current going into a junction has to equal the total current leaving
What happens if 2 identical components are connected in parallel in terms of current
They will have the same current flow through both of them
How does adding a resistor in parallel reduce the total resistance
-if u have 2 … in … their … resistance is … than the resistance of the … of the 2 …
-in parallel both … have the same …
-this means the … force making the … flow is the same as the … source for each … you …
-by adding another … the current has … than one … to go in
-this … the total current that can … around the …
-V=…. as the current … the resistance …
-if u have 2 resistors in parallel their total resistance is less than the resistance of the smallest of the 2 resistors
-in parallel both resistors have the same pd
-this means the pushing force making the current flow is the same as the pd source for each resistor you add
-by adding another loop the current has more than one direction to go in
-this increase the total current that can flow around the circuit
-V=IR as the current increases the resistance decreases
Investigating resistance in series
- Equipment list: 4 identical resistors, wires, battery, ammeter
- Build a circuit with one resistor and ammeter and a battery
- Measure the current through the circuit and calculate the resistance using V=IR
- Add another resistor into the circuit in series
- Measure the current through the circuit and use this and the pd of the battery to calculate the overall resistance
- Repeat steps 4 and 5 until all the resistors have been added
- Plot a graph of the number of resistors on the x axis and the resistance on the y axis
