Video Transcript
If a component in a circuit has a
higher electrical resistance, is it easier or harder for charges to move through
it?
What we are essentially being asked
here is to figure out what happens to moving charges in a component of a circuit if
it has a higher electrical resistance. To help us answer this, let’s look
at a typical component in a circuit diagram. This light bulb has some value of
resistance which affects how charges move through it. Given the orientation of this power
cell, we know that the direction of conventional current for this circuit should be
in the clockwise direction, which means that the direction that the electric charge
in the circuit flows in must also be in the clockwise direction.
We see that the charge is flowing
through the bulb here, meaning that the resistance of the bulb will affect its
flow. Recall that the electrical
resistance of a component or material determines how much electric charge is opposed
when trying to flow through said component or material. The SI units of resistance are
ohms, with a higher value indicating a higher resistance.
When representing a component’s
resistance value, we usually write a letter 𝑅. When this resistance opposes the
motion of the electric charge that passes through the component, larger values of
resistance will oppose the motion more, making it harder for charges to move through
it. However, no matter how large the
value of resistance is, it will not result in the current reversing direction; it
only slows the flow, meaning the current can decrease significantly, but at most it
will stop completely not reverse direction.
Now that we know a bit more about
electrical resistance, let’s look back at our question text. If we have a higher electrical
resistance in a component of the circuit, that would mean we will measure a higher
value of ohms for that component. If there is a higher electrical
resistance, the charge will be more opposed and will have a harder time moving
through the component and thus around the circuit.
It’s not just components in
circuits, though; almost all materials have some amount of inherent electrical
resistance, even the materials we build wires of the circuits with. Ideally though, we build wires out
of materials with very small values of resistance, such as copper, aluminum, or
silver. This is because higher values of
resistance would make it harder for electrical charge to move through it. The correct answer is that it is
harder.
