  A square root is a unary operation with some special properties. In the
paper, we introduce and study square roots on EMV-algebras. First, the known
properties of square roots defined on MV-algebras will be generalized for
EMV-algebras, and we also find some new ones for MV-algebras. We use square
roots to characterize EMV-algebras. Then, we find a relation between the square
root of an EMV-algebra and the square root on its representing EMV-algebra with
top element. We show that each strict EMV-algebra has a top element and we
investigate the relation between divisible EMV-algebras and EMV-algebras with a
special square root. Finally, we present square roots on tribes, EMV-tribes,
and we present a complete characterization of any square root on an MV-algebra
and on an EMV-algebra by group addition in the corresponding unital
$\ell$-group.
