Determine the relationship between length of wire and its resistance
what is the independent variable?
length of wire
What is the dependent variable?
Resistance of wire
What are the controlled variables?
thickness and type of wire
Step 1:
Connect constantan wire (resistance does not change with temperature much) to a battery or power supply using crocodile clips, along with an ammeter in series and voltmeter in parallel
Step 2:
Measure the length of wire between the crocodile clips with a metre rule (taut wire) as well as the current and voltage
Step 3:
Calculate resistance for each length using the rearranged form of Ohm’s Law and plot these against length
Analysis of graph:
The relationship between resistance and length should be DIRECTLY PROPORTIONAL
