Resistance And Resistors Flashcards
What is resistance?
How hard it is for current to pass through a circuit and is measured in ohms,
What is the independent and dependent variable in practical?
Independent is length
Dependent is resistance
Why should you place a fixed resistor in series with the piece of wire?
To limit the maximum current in circuit
To prevent a short circuit
Describe the relationship between the number of resistors used and total resistance.
Directly proportional
How would connecting resistors in parallel affect results?
Resistance would decrease as resistors was increased
It would be inversely proportional
This is because parallel increases possible roots
What is the formula?
Resistance = voltage / current
What are the steps for resistance practical.
Attach wire onto ruler with tape
Connect to circuit with clips
Record I and V every 10 cm
Plot on graph
What is the control variable.
Temperature
To prevent increase temp, switch off circuit between readings
Current
How does increasing temperature affect resistance?
The resistance of a conductor increases with temperature. This is because as the temperature increases the atomic lattice of the conductor has more energy so begins to vibrate more. This means it is more likely for any electrons travelling within the conductor to interact with atoms thus increasing its resistance.
How do we decrease resistance
Add parallel circuits
Increases number of pathways for electricity to flow
