In the primary batteries, the reaction occurs only once and after use
over a period of time battery becomes dead and cannot be reused
again The most familiar example of this type is the dry
cell (known as Leclanche cell after its discoverer) which is
used commonly in our transistors and clocks The cell
consists of a zinc container that also acts as anode and
the cathode is a carbon (graphite) rod surrounded by
powdered manganese dioxide and carbon (Fig 2