Question

A student is investigating how the resistance of a wire depends on the length of the wire

Answer 1

Answer:

When electrons travel through wires or other external circuits, they travel in a zigzag pattern that results in a collision between the electrons and the ions in the conductor, and this is known as resistance. The resistance of a wire causes difficulty for the flow of the electrical current of a wire to move and is typically measured in Ohms (Ω).

George Ohm discovered that the potential different of a circuit corresponds to the current flowing throughout a circuit, and that a circuit sometimes resists the flow of electricity. The said scientist hence came up with a rule for working out resistance, shown on the image on the side:

Resistance is an important factor to pay attention to because, one, an overly-high resistance can cause a wire to overheat due to the friction that is caused when the electrons move against the opposition of resistance, which is potentially dangerous as it could melt or even set fire. It is therefore important to take note of the resistance when dealing with wires to supply power to a device or so. A real life application would be a toaster where the wires are sized to get hot enough to toast bread but not enough to melt. Secondly, resistance can also be used a very useful tool that enables you to control certain things. An example from the real life world would be LED lights that requires a resistor to control the flow of the electrical current to prevent getting damaged by high electrical current. Another example would be the volume control on a radio where a resistor is used to portion out the signal of it which allows you to control the volume level.  

It is clear now that resistance is an important attribute that has been applied to many forms of technology to perform a useful function, and this experiment aims to see how we can control it. The resistance of a wire varies according to the four factors of the wire; they are the temperature, material, diameter/thickness and length of the wire. This experiment will be focusing specifically on that last factor – length – and investigate just how much of a role a length of a wire would have on its electrical resistance by using a range of wire lengths to test with.

Explanation: