Video Transcript
Complete the following sentence:
The conventional current in a wire is in the blank the flow of electrons in the
wire. (A) Opposite direction to, (B) same
direction as.
Okay, so in this question, we’re
being asked about the current in a wire. So let’s start by drawing a sketch
of a wire. So in this sketch, the red circles
represent the nuclei of the atoms in the wire, and the blue circles represent the
electrons in the wire. The question tells us that in the
wire, there is a flow of electrons. So let’s assume that in our wire,
the electrons are flowing to the right, so in the direction of this arrow. So all of our electrons are moving
in the same direction, which in this case is to the right.
We can recall that electric current
is the flow of electric charge in a material. In our wire, this electric charge
is in the direction of the electron flow, so it’s to the right. But let’s also recall that
conventional current, which is what this question is asking about, is defined in the
same way as electric current. But the direction of the
conventional current is in the opposite direction to the flow of electrons in the
material. So for our wire, if the electrons
are flowing to the right, this means the conventional current in the wire must be to
the left. And therefore, we have our answer
to this question. And that answer is (A) opposite
direction to. And so our full completed sentence
reads: The conventional current in a wire is in the opposite direction to the flow
of the electrons in the wire.
