Resistance of a wire
This practical lesson covers:
- How to identify the relationship between length of a wire and its resistance
Investigating the relationship between wire length and resistance Aim: To investigate the relationship between the length of a wire and its resistance. |
Background information: Wires are not perfect conductors of electricity as they have some resistance. In this practical, you will investigate how a wire's resistance varies with length by measuring the current flowing through the wire and the potential difference across it. |
Variables:
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Which of the following is connected in parallel with the wire being measured?
voltmeter
power supply
ammeter
variable resistor
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What is the independent variable in this experiment?
resistance of the wire
current flowing through the wire
length of the wire
voltage across the wire
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What is the purpose in plotting a graph of resistance against length?
to work out the relationship between voltage and resistance
to work out the relationship between voltage and current
to work out the relationship between length and resistance
to work out the relationship between length and voltage
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Which of the following would be a valid conclusion for this experiment?
as the length of the wire increases, the resistance of the wire increases exponentially
as the length of wire increases, the resistance of the wire decreases exponentially
as the length of the wire increases, the resistance of the wire decreases linearly
as the length of the wire increases, the resistance of the wire increases linearly
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Which of the following would result not improve the accuracy of the data?
use a ruler with a mm scale instead of a cm scale
attaching the wire to the meter ruler to make it easier to measure the length
ensuring the current continues to flow between readings
using a voltmeter with a greater precision
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