How does the length of a piece of Nachrome wire affect its electrical resistance.
AIM:
To investigate how the electrical resistance of a wire changes in relationship to its length.
DEFINITION OF RESISTANCE:
Electrons move more easily through some conductors than other when a p.d is applied. The opposition of a conductor to current is called its resistance. A good conductor has a low resistance and a poor conductor has a high resistance. The resistance of a wire of a certain material.
* Increases as its length increases
* Increases as its cross-sectional area decreases
* Depends on the material.
FACTORS AFFECTING THE RESISTANCE OF A WIRE:
Factor
How does this affect the resistance?
Length of the wire
If you double the length of the wire this doubles the resistance, since twice the length of wire is equivalent to two equal resistances in series. The resistance of a wire is therefore proportional to its length.
Thickness of the wire
Thick wires are equivalent to a number of thinner wires of equal area joined in parallel. The resistance of a wire is inversely proportional to its area of cross-section.
Material
The material of which the wire is composed is another important factor to be considered when deciding the length and gauge of wire for a particular resistance. Silver is the best conductor, but copper, the next best, is cheaper and is used for connecting wire and in electric cables.
Resistors are used in circuits to limit the current in each branch of a circuit. I f resistor is replaced by one of lower resistance in a circuit, the current will be greater and this may cause overheating and damage to other components in the circuit.
(Key Science - Jim Breithaupt)
PREDICTION:
I predict that as the length of the wire increases so to will the resistance of it. I also believe that the rate at which the length of the wire increases will be directly proportional to the resistance of the wire. So if you double the length of the wire this doubles to resistance.
AIM:
To investigate how the electrical resistance of a wire changes in relationship to its length.
DEFINITION OF RESISTANCE:
Electrons move more easily through some conductors than other when a p.d is applied. The opposition of a conductor to current is called its resistance. A good conductor has a low resistance and a poor conductor has a high resistance. The resistance of a wire of a certain material.
* Increases as its length increases
* Increases as its cross-sectional area decreases
* Depends on the material.
FACTORS AFFECTING THE RESISTANCE OF A WIRE:
Factor
How does this affect the resistance?
Length of the wire
If you double the length of the wire this doubles the resistance, since twice the length of wire is equivalent to two equal resistances in series. The resistance of a wire is therefore proportional to its length.
Thickness of the wire
Thick wires are equivalent to a number of thinner wires of equal area joined in parallel. The resistance of a wire is inversely proportional to its area of cross-section.
Material
The material of which the wire is composed is another important factor to be considered when deciding the length and gauge of wire for a particular resistance. Silver is the best conductor, but copper, the next best, is cheaper and is used for connecting wire and in electric cables.
Resistors are used in circuits to limit the current in each branch of a circuit. I f resistor is replaced by one of lower resistance in a circuit, the current will be greater and this may cause overheating and damage to other components in the circuit.
(Key Science - Jim Breithaupt)
PREDICTION:
I predict that as the length of the wire increases so to will the resistance of it. I also believe that the rate at which the length of the wire increases will be directly proportional to the resistance of the wire. So if you double the length of the wire this doubles to resistance.
