Is there any homomorphism $h$ from $A \rightarrow B$, such that $A$ has an identity $e$ and $h(e)$ is not an identity in $B$?
($A$ and $B$ are Algebras)
Edit: I gave my teacher the same proof given below in the answers, but she argued that it's possible by giving the following example, Let $A = (N,+)$ and $B = (N, .)$ where N is the set of natural numbers and $.$ is the multiply operator, $h: A \rightarrow B$, be a homomorphism such that, $h(a) = 0$ for all $a$ belonging to A, so as 0 is the identity in $A$ and 1 is identity in $B$, but $h(0) = 0$ according to homomorphism, as $h(a) != 1$ , so this proof fails in this case, can you prove why you solution is correct.
Let $h$ be a homomorphism between $A$ and $B$. Then $h(xy) = h(x)h(y)$, so $h(x) = h(ex) = h(e)h(x)$, thus $h(e)$ must be an identity in $B$.