Question

what is a dynamo? write its one use?

Answer 1

dynamo is the battery which stores current. it is used to store energy produce by any source.

Answer 2

HAY FRIEND HERE IS YOUR ANSWER
A machine for converting mechanical energy into electrical energy, typically by means of rotating coils of copper wire in a magnetic field.
N it's use Dynamos still have some uses in low power applications, particularly where low voltage DC is required, since an alternator with a semiconductor rectifier can be inefficient in these applications.

Hand cranked dynamos are used in clockwork radios, hand powered flashlights, mobile phone rechargers, and other human powered equipment to recharge batteries.