### Video Transcript

Which of the following is the unit
of electric current? (A) The meter, (B) the ampere, (C)
the coulomb, (D) the watt, (E) the second.

Units are an important part of
every physics problem. Not only do they communicate the
exact type of quantity we are working with, but they can also include clues to help
solve the problems. If we can identify the type of unit
that the answer should have, then we can sometimes determine how to find the answer
to the problem.

This question is asking for the
unit of electric current. Let’s start by looking at a simple
circuit. The simple circuit has a voltage
source, with the positive terminal and negative terminal connected by a square
wire. When the circuit is connected in
this way, electric charge flows through the wire. This flow of electric charge is
called a current, usually labeled with the symbol 𝐼.

The unit for electric current is
the ampere, named after a scientist that did a lot of work on electricity,
André-Marie Ampère. The value of the current in a
circuit indicates the amount of charge that flows past a point in the circuit every
second. If one coulomb of charge flows past
a point every second, then there is one ampere of current in the circuit.

So the correct answer for this
question is (B), the ampere.