Investigating resistance Flashcards
investigate adding resistance in series
PRACTICAL
1-6
LOOK AT DIAGRAM ON PG 184
1) find 4 identical resistors
2) build circuit with 1 resistor and take note of pd of battery
3) measure current through ammeter and calculate resistance, r = v/i
4) add another resistor in series w the first
5) again measure current through circuit using Ammeter and pd of battery to work out overall resistance of circuit
6) Repeat steps 4-5 until all resistors are plugged in
Plot graph of number of individual resistors against total resistance of circuit
or in parallel
1-6
1) use same equipment so fair test and build same initial circuit
2) measure total current through circuit and of resistance of circuit, R=V/I ( V = PD of battery )
3) Add another resistor in parallel w the first
4) Measure total current through circuit and use PD of battery to work out overall resistance of circuit
5) Repeat steps 3-4 until all resistors are plugged in
Plot graph of number of individual resistors against total resistance of circuit
results of series
adding resistor in series increases total resistance of circuit.
The more resistance you add, the larger the resistance of the whole circuit
Straight line in graph
results of parallel
When adding resistor in parallel , the total current through the circuit increases so total resistance of the circuit has decreased
The more resistors you add, the smaller the overall resistance becomes
Check page 185 of graph
