Video Transcript
The diagram below shows two
identical batteries connected in parallel. The emf of each battery is one
volt. What is the total emf provided by
the batteries? (A) One volt, (B) two volts, or (C)
four volts.
In this question, we’re shown a
circuit containing two batteries that each have the same emf or electromotive
force. The batteries are connected in
parallel, and we need to determine the total emf of the circuit.
First, we can recall that a battery
is a set of cells connected in series with each other like this. A battery effectively behaves like
a single cell, and we can work out the emf of a battery simply by adding up the emfs
of all the individual cells. In this question, we have two
batteries, each with an emf of one volt. But these two batteries are
connected in parallel, rather than in series. This means that we don’t just add
up their emfs to work out the total emf.
When we have identical batteries
connected in parallel, we need to remember that as long as they’re properly
connected, the total emf is equal to the emf of any one battery. Here, we can see that the batteries
are properly connected, since they have their positive terminals oriented in the
same direction. They also have identical emfs of
one volt. This means that the total emf of
the circuit shown is equal to the emf of one battery on its own.
So our final answer is option
(A). The total emf provided by the
batteries is one volt.
